Sensor apparatus systems, devices and methods

ABSTRACT

A sensor apparatus and sensor apparatus system for use in conjunction with a cassette, including a disposable or replaceable cassette. In some embodiments, the cassette includes a thermal well for permitting the sensing of various properties of a subject media. The thermal well includes a hollow housing of a thermally conductive material. In other embodiments, the cassette includes sensor leads for sensing of various properties of a subject media. The thermal well has an inner surface shaped so as to form a mating relationship with a sensing probe. The mating thermally couples the inner surface with a sensing probe. In some embodiments, the thermal well is located on a disposable portion and the sensing probe on a reusable portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of patent application Ser.No. 11/871,821, filed Oct. 12, 2007 now abandoned and entitled SensorApparatus Systems, Devices and Methods, which application claimspriority from the following United States Provisional PatentApplications, all of which are hereby incorporated herein by referencein their entireties:

U.S. Provisional Patent Application No. 60/904,024 entitled HemodialysisSystem and Methods filed on Feb. 27, 2007; and

U.S. Provisional Patent Application No. 60/921,314 entitled SensorApparatus filed on Apr. 2, 2007.

This application is also related to the following United States PatentApplications, and are hereby incorporated herein by reference in theirentireties:

U.S. patent application Ser. No. 11/871,712, filed Oct. 12, 2007entitled Pumping Cassette; U.S. patent application Ser. No. 11/871,787,filed Oct. 12, 2007 and entitled Pumping Cassette; U.S. patentapplication Ser. No. 11/871,793, filed Oct. 12, 2007 and entitledPumping Cassette; U.S. patent application Ser. No. 11/871,803, filedOct. 12, 2007 and issued as U.S. Pat. No. 7,967,022 on Jun. 28, 2011 andentitled Cassette System Integrated Apparatus; U.S. patent applicationSer. No. 11/871,828, filed Oct. 12, 2007 and entitled PeritonealDialysis Sensor Apparatus, Systems, Devices and Methods;

U.S. patent application Ser. No. 12/038,648, filed Feb. 27, 2008 andissued as U.S. Pat. No. 8,042,563 on Oct. 25, 2011 and entitled CassetteSystem Integrated Apparatus; and U.S. patent application Ser. No.12/072,908, filed Feb. 27, 2008 and issued as U.S. Pat. No. 8,246,286 onAug. 21, 2012 and entitled Hemodialysis System and Methods.

TECHNICAL FIELD

The present invention relates to sensor systems, devices, and methods,and more particularly to systems, devices, and methods for sensors,sensor apparatus, and sensor apparatus systems.

BACKGROUND ART

In many applications, the temperature of a media, whether a solid,liquid or gas, is determined. One method is introducing a temperaturesensor apparatus or probe to the medium being measured. For accuracy,close proximity of the sensor to the subject media is desired. However,this method may lead to contamination of the sensor apparatus and/or thefluid. Additional problems with harsh media or problems with theaccuracy of the device used exist.

The concentration of a known compound in a media, whether fluid orotherwise, can be determined through measuring the conductivity of thefluid. Determining the conductivity of a material can also provideuseful information such as the composition or presence of a particularcompound in a material or irregularities in the conductive materialbetween conductivity sensing probes. The presence, absence or variationof conductivity can also be a useful determinant of anomalies in asystem.

There is a need for an apparatus that can both sense the temperature andthe conductivity of a fluid or other media. There is a desire for acombination temperature and conductivity sensor that avoid contaminationwith the subject media and is compact. Also, there is a desire for anaccurate temperature sensing device.

Additionally, there is a need for an accurate measurement apparatus tomeasure the temperature, conductivity, and/or other condition of asubject media while avoiding contamination between with the measurementapparatus and the subject media. There is also a need for an accuratemeasurement apparatus that can measure the temperature, conductivity,and/or other condition of a subject media where such subject media iscontained in and/or flowing through a disposable component such thatpart or all of the sensor apparatus can be reused and need not bedisposed of along with the disposable component.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention there is provided asensor apparatus system for determining one or more properties of asubject fluid in a cassette, the system comprising a probe housing; athermal sensor in said probe housing having a sensing end and aconnector end; a probe tip thermally coupled to said sensing end of thethermal sensor and attached to said probe housing, the probe tip adaptedfor thermal coupling with an inner surface of a well installed in acassette; and at least two leads connected to said connector end of saidthermal sensor, whereby thermal energy is transferred from said well tosaid thermal sensor and whereby temperature information is conveyedthrough said leads. In various alternative embodiments, the sensingprobe may further include a third lead attached to one of the probehousing, the thermal sensor, and the probe tip for permittingconductivity sensing. Alternatively, the sensing probe may furtherinclude a conductivity sensor attached to one of the probe housing, thethermal sensor, and the probe tip for permitting conductivity sensing;and a third lead attached to the conductivity sensor for transmittingconductivity information. A urethane resin may be included between saidprobe tip and said probe housing. The probe tip may include a flange formating with the housing.

In various alternative embodiments of the sensor apparatus systemdescribed above, thermal epoxy may be included between said thermalsensor and said probe tip. The probe tip may be copper, steel, or ametal including at least one of silver, copper, steel, and stainlesssteel. In various embodiments, the housing may be plastic or metal. Thehousing may include a flange disposed about said probe housing, and aspring may be used in conjunction with the flange. The housing mayinclude an integrated flexible member.

Some embodiments of this aspect of the present invention include a wellof a predetermined size and shape. The well mates with the probe and theprobe tip is thermal coupled to said well.

In accordance with one aspect of the present invention the well includesa hollow housing of a thermally conductive material. The housing has anouter surface and an inner surface. The inner surface is a predeterminedshape so as to form a mating relationship with a sensing probe. Themating thermally couples the inner surface with a sensing probe.

Some embodiments of this aspect of the present invention include apredetermined volume of thermal grease on the inner surface of the well.

In accordance with one aspect of the present invention, method fordetermining temperature and conductivity of a subject media in acassette is described. The method includes the following steps:installing at least one well in a cassette; thermally coupling a welland a sensing probe such that temperature and conductivity can bedetermined; transferring thermal and conductivity signals through atleast 3 leads from the sensing probe; and determining temperature andconductivity using the signals.

In accordance with another aspect of the present invention, a method fordetecting air in a fluid line contained in a cassette is described. Themethod includes the following steps: installing at least one well in acassette; thermally coupling at least two wells located in a fluid lineto sensing probes such that temperature and conductivity can bedetermined; transferring conductivity signals through at least 3 leadsfrom the sensing probes; determining conductivity for each sensingprobe; calculating the difference of conductivity from each sensingprobe; and determining if the difference exceeds a threshold.

In accordance with another aspect of the invention there is providedapparatus comprising a fluid conduit in a cassette including a well forat least one of transmitting temperature and permitting conductivitysensing of fluid passing through the conduit, wherein the well isadapted for interconnection with a sensor.

In various alternative embodiments, the apparatus may be configured sothat a portion of the well comes into contact with fluid in the conduitor so that no portion of the well comes into contact with fluid in theconduit. The fluid conduit in the cassette may include plastic tubing ormetal tubing.

In various embodiments, the cassette containing the fluid line comprisesa rigid body overlaid on one or more sides with a flexible diaphragm. Invarious embodiments the flexible diaphragm cassette includes one or morepump chambers and/or one or more value stations. In various embodiments,one or more wells are positioned on the edge of the cassette. In certainof these embodiments, one or more wells are positioned on the bottomedge of the cassette.

In various embodiments, the cassette has a rigid front and/or backplate. One or more wells may be installed in the rigid cassette.Alternatively, one or more sensor leads may be installed in the rigidcassette. In various embodiments, the rigid cassette may contain one ormore pod pumps.

The cassette and the well may be integrally formed from the samematerial.

Alternatively, the well may be coupled to the cassette, e.g., using atleast one of press fit connection, flexible tabs, adhesive, ultrasonicweld, and a retaining plate and fastener. An o-ring may be disposedbetween the well and the fluid conduit. The o-ring may include one of around cross-section, a square cross-section, and an X-shapedcross-section. The well may include a groove to receive a portion of theo-ring. A portion of the well in contact with the conduit may beflexible so as to deform the conduit and may include a plurality of cutsto provide such flexibility.

In accordance with another aspect of the invention there is provided afluid pumping apparatus comprising at least one pump and a well for atleast one of transmitting temperature and permitting conductivitysensing of fluid passing through the conduit, wherein the well isadapted for interconnection with a sensor. In various alternativeembodiments, the at least one pump may include at least one pod pump andmay include a pair of pod pumps. The at least one pump and the well maybe integrated into a cassette.

In accordance with another aspect of the invention there is provided asensing system comprising at least one sensing probe and at least onewell installed in a cassette, the well in communication with the sensingprobe for at least one of thermal sensing and conductivity sensing.

In accordance with another aspect of the invention there is provided asensor manifold comprising a cassette and at least one sensing probe forat least one of thermal sensing and conductivity sensing. In variousembodiments, the sensor manifold contains two or more fluid paths andtwo or more sensing probes for at least one of thermal sensing andconductivity sensing. In various embodiments, the sensor manifold ispassive with respect to controlling the flow of the fluid in the fluidpaths within the cassette. In such embodiments, the sensor manifold maybe free from valves and pumping mechanisms. In various embodiments, thesensor manifold may comprise a cassette with a rigid front and/or backplate and a mid-plate. In various embodiments, the sensor manifold maycomprise electrical circuits connected to the sensing probes. In certainof these embodiments, the sensor manifold may comprise a printed circuitboard.

These aspects of the invention are not meant to be exclusive orcomprehensive and other features, aspects, and advantages of the presentinvention are possible and will be readily apparent to those of ordinaryskill in the art when read in conjunction with the followingdescription, the appended claims, and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features of the invention wilt be more readily understoodby reference to the following detailed description, taken with referenceto the accompanying drawings, wherein:

FIGS. 1A and 1B are embodiments of the sensing apparatus where thethermal well is a continuous part of the fluid line;

FIGS. 2A and 2B are embodiments of the sensing apparatus where thethermal well is a separate part from the fluid line;

FIGS. 3A and 3B are embodiments of the sensing apparatus showing variouslengths and widths of the thermal well;

FIG. 4 is a pictorial view of a thermal well according to one embodimentof the sensing apparatus;

FIG. 5 is a cross sectional view of an exemplary embodiment of thethermal well;

FIGS. 6A and 6B show section views of embodiments of thermal wellshaving variable wall thickness;

FIGS. 7A-7S are sectional views of various embodiments of the thermalwell embedded in a fluid line;

FIG. 8 is a section side view of one embodiment of the sensing probe;

FIG. 9 is an exploded view of the embodiment shown in FIG. 8;

FIG. 10 is a sectional view of an alternate embodiment of the tip of thesensing probe;

FIG. 11A is an alternate embodiment of the sensing probe;

FIG. 11B is an alternate embodiment of the sensing probe;

FIG. 12 is a side view of an alternate embodiment of the sensing probe;

FIG. 13A is a section view of a sensing probe coupled to a thermal well;

FIG. 13B is an alternate embodiment of the sensing probe shown in FIG.13A;

FIG. 14A is a section view of a sensing probe as shown in FIG. 8 coupledto a thermal well;

FIG. 14B is an alternate embodiment of the sensing probe shown in FIG.14A;

FIG. 15 is a sectional view of one exemplary embodiment of the sensorapparatus;

FIG. 16 shows an alternate embodiment of a sensing probe coupled to athermal well;

FIG. 17 is a section view of one embodiment of a sensing probe coupledto a thermal well and suspended by a spring;

FIG. 18 is a section view of one embodiment of a sensing probe in ahousing;

FIG. 19 is a section view of one embodiment of a sensing probe in ahousing;

FIG. 20 is a section view of one embodiment of a sensing probe in ahousing;

FIG. 21 is a side view of a fluid line including two sensors;

FIG. 22 is a section view of a fluid line with a sensor apparatus;

FIG. 23A is a section view of the back side of an exemplary cassette;

FIG. 23B is a side view of the side of an exemplary cassette;

FIG. 23C is a section view of the front of an exemplary cassette;

FIG. 24 is a view of an exemplary cassette and thermal wells;

FIG. 25 is a view of an exemplary cassette with thermal wells installed;

FIG. 26 is a view of the thermal wells extending into a fluid line of anexemplar cassette;

FIG. 27 is a close up certain features of FIG. 26;

FIG. 28 is a section view of one embodiment of a sensing probe coupledto a thermal well installed in a cassette and suspended by a spring;

FIG. 29 is a sectional view of one embodiment of a pod-pump that isincorporated into embodiments of cassette;

FIG. 30A is a front and isometric view of the exemplary embodiment ofthe fluid side of the midplate of the cassette;

FIG. 30B is a front and isometric view of the exemplary embodiment ofthe air side of the midplate of the cassette;

FIG. 31A is a front and isometric view of the exemplary embodiment ofthe inner side of the bottom plate of the cassette;

FIG. 31B is a front and isometric view of the exemplary embodiment ofthe outer side of the bottom plate of the cassette;

FIG. 31C is a side view of the exemplary embodiment of the midplateplate of the cassette;

FIG. 32A is a top view of the assembled exemplary embodiment of thecassette;

FIG. 32B is a bottom view of the assembled exemplary embodiment of thecassette;

FIG. 32C is an exploded view of the assembled exemplary embodiment ofthe cassette;

FIG. 32D is an exploded view of the assembled exemplary embodiment ofthe cassette;

FIGS. 33A-33C show cross sectional views of the exemplary embodiment ofthe assembled cassette

FIG. 34 is a perspective view of a system having a base unit with adisposable unit containing a manifold according to one embodiment of theinvention;

FIG. 35 is a perspective view of the disposable unit containing amanifold shown in FIG. 34;

FIG. 36A is a perspective view of the components from the system of FIG.34;

FIG. 36B is a perspective, back-side cross-sectional view of themanifold of FIGS. 35 and 38A-B, in accordance with an exemplaryembodiment of the present invention;

FIG. 36C shows a thermal well that may be used in the manifold of FIGS.35, 36B, 38A and 38B in the heat-exchanger of FIG. 35, in accordancewith an exemplary embodiment of the present invention;

FIG. 37 shows a view of the manifold interface, in accordance with anexemplary embodiment of the present invention;

FIGS. 38A and 38B respectively show a perspective back-side view and aperspective bottom view of the manifold from FIG. 35, in accordance withan exemplary embodiment of the present invention;

FIG. 39 is a view of an exemplary sensor manifold; and

FIG. 40 is a view of another exemplary sensor manifold.

FIG. 41 is a view of another exemplary sensor manifold.

FIG. 42 is a view of the fluid paths within the exemplary sensormanifold shown in FIG. 41.

FIG. 43 is a side view of the exemplary sensor manifold shown in FIG.41.

FIG. 44A is a cross sectional view of the exemplary sensor manifoldshown in FIG. 41 at cross section A-A of FIG. 44B.

FIG. 44B is a front view of the exemplary sensor manifold shown in FIG.41.

FIG. 45 is an exploded view of the exemplary sensor manifold shown inFIG. 41.

FIG. 46 is a view of a printed circuit board and media edge connector inaccordance with the exemplary sensor manifold shown in FIG. 41.

FIG. 47 is an exemplary fluid schematic of a hemodialysis system.

It should be noted that the foregoing figures and the elements depictedtherein are not necessarily drawn to consistent scale or to any scale.Unless the context otherwise suggests, like elements are indicated bylike numerals.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Definitions. As used in this description and the accompanying claims,the following terms shall have the meanings indicated, unless thecontext otherwise requires:

“Spheroid” means any three-dimensional shape that generally correspondsto a oval rotated about one of its principal axes, major or minor, andincludes three-dimensional egg shapes, oblate and prolate spheroids,spheres, and substantially equivalent shapes.

“Hemispheroid” means any three-dimensional shape that generallycorresponds at approximately half a spheroid.

“Spherical” means generally spherical.

“Hemispherical” means generally hemispherical.

“Fluid” shall mean a substance, a liquid for example, that is capable ofbeing pumped through a flow line. Blood is a specific example of afluid.

A “patient” includes a person or animal from whom, or to whom, fluid ispumped, whether as part of a medical treatment or otherwise.

“Subject media” is any material, including any fluid, solid, liquid orgas, that is in contact directly with a sensing probe or indirectly viathermal wells, sensor extension pins, and other such devices fortransferring information regarding one or more characterstics of suchsubject media to one or more sensors.

Various aspects of the present invention are described below withreference to various exemplary embodiments. It should be noted thatheadings are included for convenience and do not limit the presentinvention in any way.

Various embodiments of sensors, including thermal and/or conductivitysensors, are described. Such thermal/conductivity sensors can be used ina wide variety of applications and are by no means limited tothermal/conductivity measurements of fluids or to thermal/conductivitymeasurements in any particular context. Additionally, variousembodiments of systems, devices, and methods for sensor interface,including direct sensor contact, sensor interface through the use of athermal well, or otherwise with various disposable and reusablecomponents are described. Such systems, devices, and methods for sensorinterface can be used with a wide variety of sensors and in a widevariety of applications. Such systems, devices, and methods for sensorinterface are by no means limited to use with the various sensorembodiments or for use in any particular context.

1. Thermal Wells

In one exemplary embodiment, a thermal well is used to accommodate asensor probe, such as a temperature sensing probe. The thermal wellcomes into direct contact with a subject media (e.g., a liquid such asblood or dialysate) and the sensing probe does not. Based on heattransfer dictated in large part by the thermodynamic properties of thethermal well and sensing probe construction, the sensing probe candetermine the properties of the subject media without coming into directcontact with the subject media. The accuracy and efficiency of thesensor apparatus arrangement depends on many factors including, but notlimited to: construction, material and geometry of both the probe andthe thermal well.

Referring now to FIGS. 1A and 1B, two embodiments of the sensorapparatus which includes the thermal well 5100 and the sensing probe5102, are shown in relation to a fluid line 5108. In these embodiments,the thermal well 5100 is integrated into the fluid line 5108. However,in other embodiment, some described below, the thermal well 5100 is notcompletely integrated into the fluid line 5108, i.e., the thermal well5100 can be made from different materials as compared with the fluidline 5108. In alternate embodiments, the thermal well 5100 is notintegrated into any fluid line but can be integrated into anything ornothing at all. For example, in some embodiments, the thermal well 5100can be integrated into a container, chamber, machine, protective sleeve,fluid pump, pump cassette, disposable unit, manifold, or other assembly,sub-assembly, or component. For purposes of the description, anexemplary embodiment is described for illustrative purposes. Theexemplary embodiment includes the embodiment where the thermal well 5100is in a fluid line. However, the sensor apparatus and the thermal wellcan be used outside of a fluid line.

Referring now to FIG. 1A, a side view showing a thermal well 5100 formedin a fluid line 5108 which provides the space 5104 for subject media toflow through, and a sensing probe 5102 is shown. Data from the sensingprobe is transmitted using at least one lead 5106. An end view of FIG.1A is shown in FIG. 1B.

In this embodiment, the thermal well 5100 is one piece with the fluidline 5108. The total area of the thermal well 5100 can vary. By varyingthe geometry of the thermal well 5100, the variables, including, but notlimited to, the thermal conductivity characteristic of the thermal well5100 and thus, the heat transfer between the thermal well 5100 and thesensing probe 5102 will vary. As described in more detail below, thematerial construction of the thermal well 5100 is another variable inthe sensor apparatus.

In some embodiments, the fluid line 5108 is made from a material havinga desired thermal conductivity. This material may vary depending on thepurpose. The material can be anything including, but not limited to, anyplastic, ceramic, metals or alloys of metals or combinations thereof.

Referring now to FIGS. 2A and 2B, in these embodiments, the fluid line5108 and the thermal well 5100 are separate parts. In some embodiments,the fluid line 5108 and the thermal well 5100 are made from differentmaterials.

FIGS. 1A-1B and FIGS. 2A-2B show relatively simple embodiments of thesensor apparatus. Thus, for these embodiments, the sensing apparatusincludes a thermal well 5100 and a sensing probe 5102 where the thermalwell either is integrated as one continuous part with the fluid line5108 or is a separate part from the fluid line 5108. However, manyembodiments of the sensor apparatus are contemplated. Much of thevarious embodiments include variations on the materials and thegeometries of the thermal well 5100 and/or the sensing probe 5102. Thesevariations are dictated by multiple variables related to the intendeduse for the sensor apparatus. Thus, the subject media and theconstraints of the desired sensor, for example, the accuracy, time forresults and the fluid flow and subject media characteristics are but asampling of the various constraints that dictate the embodiment used. Inmost instances, each of the variables will affect at least one part ofthe embodiment of the sensor apparatus.

Thus, multiple variables affect the various embodiments of the sensorapparatus, these variables include but are not limited to: 1) geometryof the thermal well; 2) material composition of the thermal well; 3)material composition of the sensing probe; 4) desired flow rate of thesubject media; 5) length and width of the thermal well; 6) desiredaccuracy of the sensing probe; 7) wall thicknesses; 8) length and widthof the sensing probe; 9) cost of manufacture; 10) subject mediacomposition and characteristics including tolerance for turbulence; 11)geometry of sensing probe; and 12) desired speed of readings.

In the foregoing, various embodiments of the sensor apparatus aredescribed. The description is intended to provide information on theaffect the variables have on the sensor apparatus embodiment design.However, these are but exemplary embodiments. Many additionalembodiments are contemplated and can be easily designed based on theintended use of the sensor apparatus. Thus, by changing one or more ofthe above mentioned partial list of variables, the embodiment of thesensor apparatus may vary.

Referring now to FIGS. 3A and 3B, two embodiments of the thermal well5100 are shown as different parts from the fluid line 5108. Theseembodiments show two geometries of the thermal well 5100. In FIG. 3A,the geometry includes a longer thermal well 5100. In FIG. 3B, thethermal well 5100 geometry is shorter. The length and width of thethermal well 5100 produce varying properties and accuracies of thethermal conductivity between the thermal well 5100 and the sensing probe5102. Depending on the use of the sensor apparatus, the thermal well5100 geometry is one variable.

Referring now to FIG. 3A, the longer thermal well 5100 generallyprovides a greater isolation between the subject media temperature inthe fluid line 5104 and the ambient temperature. Although the longerthermal well 5100 geometry shown in FIG. 3A may be more accurate, theembodiment shown in FIG. 3B may be accurate enough for the purpose athand. Thus, the length and width of the thermal well 5100 can be anylength and width having the desired or tolerable accuracycharacteristics. It should be understood that two extremes of length areshown in these embodiments; however, any length is contemplated. Thedescription herein is meant to explain some of the effects of thevariables.

Still referring to FIGS. 3A and 3B, the longer thermal well 5100 shownin FIG. 3A may impact the fluid flow of the subject media in the fluidline 5108 to a greater degree than the embodiment shown in FIG. 3B. Itshould be understood that the length of the thermal well 5100 may alsoimpact the turbulence of the fluid flow. Thus, the length and width ofthe thermal well 5100 may be changed to have greater or lesser impact onthe fluid flow and turbulence of the fluid, while mitigating the othervariables.

The shape of the thermal well 5100 is also a variable. Any shape desiredis contemplated. However, the shape of the thermal well 5100, as withthe other variables, is determined in part based on the intended use ofthe sensor apparatus. For purposes of description, an exemplaryembodiment is described herein. However, the shape in the exemplaryembodiment is not meant to be limiting.

Referring now FIG. 4 for purposes of description, the thermal well 5100has been divided into 3 zones. The top zone 5402 communicates with thesensing probe (not shown); the middle zone 5404 provides the desiredlength of the thermal well 5100. As described above, the length maydictate the level of protrusion into the fluid path. The length isdictated in part by the desired performance characteristics as discussedabove. The middle zone 5404 also isolates the top zone 5402 from theambient. The middle zone 5404 may also serve to locate, fasten or sealthe thermal well 5100 into the fluid line (shown as 5108 in FIGS.1A-1B).

The bottom zone 5406, which in some embodiments may not be necessary(see FIG. 7K) thus, in these embodiments, the middle zone 5404 and thebottom zone 5406 may be a single zone. However, in the exemplaryembodiment, the bottom zone 5406 is shaped to aid in press fitting thethermal well into an area in the fluid line and may locate and/or fastenthe thermal well 5100 into the fluid line 5108. In other embodiments,zone 5406 may be formed to facilitate various joining methods (see FIGS.7A-7J, 7L-7S)

Referring now to FIG. 5 a cross section of the exemplary embodiment ofthe thermal well 5100 is shown. The dimensions of the exemplaryembodiment of the thermal well 5100 include a length A of approximately0.113 inches (with a range from 0-0.379 inches), a radius B ofapproximately 0.066 inches and a wall thickness C ranging fromapproximately 0.003-0.009 inches. These dimensions are given forpurposes of an exemplary embodiment only. Depending on the variables andthe intended use of the sensing apparatus, the thermal well 5100dimensions may vary, and the various embodiments are not necessarilyproportional.

In some embodiments, the wall thickness can be variable, i.e., the wallthickness varies in different locations of the thermal well. Althoughthese embodiments are shown with variable thicknesses in variouslocations, this is for description purposes only. Various embodiments ofthe thermal well may incorporate varying wall thickness in response tovariables, these varying wall thicknesses can be “mixed and matched”depending on the desired properties of the sensing apparatus. Thus, forexample, in some embodiments, a thinner zone 5404 may be used withthinner zone 5406 and vice-versa. Or, any other combination of “thinner”and “thicker” may be used. Also, the terms used to describe the wallthicknesses are relative. Any thickness desired is contemplated. Thefigures shown are therefore for descriptive purposes and represent twoembodiments where many more are contemplated.

Referring now to FIGS. 6A and 6B, zone 5402 can be thicker or thinner asdesired. The thinner zone 5402, amongst other variables, generallyprovides for a faster sensing time while a thicker zone may be usefulfor harsh environments or where sensor damping is desired. Zone 5404 maybe thicker, amongst other variables, for greater strength or thinnerfor, amongst other variables, greater isolation from ambient. Zone 5406can be thinner or thicker depending on the fastening method used.

The thermal well 5100, in practice, can be embedded into a fluid line5108, as a separate part from the fluid line 5108. This is shown anddescribed above with respect to FIGS. 2A-2B. Various embodiments may beused for embedding the thermal well 5100 into the fluid line 5108.Although the preferred embodiments are described here, any method orprocess for embedding a thermal well 5100 into a fluid line 5108 can beused. Referring now to FIGS. 7A-7S, various configurations for embeddingthe thermal well 5100 into the fluid line 5108 are shown. For theseembodiments, the thermal well 5100 can be made from any materials,including but not limited to, plastic, metal, ceramic or a combinationthereof. The material may depend in some part on the compatibility withthe intended subject media. The fluid line 5108, in these embodiments,may be made from plastic, metal, or any other material that iscompatible with the subject media.

Referring first to FIG. 7A, the thermal well 5100 is shown press fitinto the fluid line 5108 using the zone 5404 (shown in FIG. 4). In FIG.7B, the thermal well 5100 is shown press fit into the fluid line 5108using the zone 5406. Referring now to FIG. 7C, the thermal well 5100 isshown retained in the fluid line 5108 with flexible tabs 5704, an O-ringis also provided. Referring now to FIG. 7D, the thermal well 5100 isshown inserted into the fluid line 5108 with an O-ring 5702. The thermalwell 5100 is also shown as an alternate embodiment, where the thermalwell 5100 zone 5406 includes an O-ring groove. The O-ring groove can becut, formed, spun, cast or injection molded into the thermal well, orformed into the thermal well 5100 by any other method. FIG. 7E shows asimilar embodiment to that shown in FIG. 7D, however, the O-ring grooveis formed in zone 5406 rather than cut, molded or cast as shown in FIG.7D.

Referring now to FIG. 7F, the thermal well 5100 is shown press fit intothe fluid line 5108, zone 5406 includes flexibility allowing the edge ofzone 5406 to deform the material of the fluid line 5108. Referring nowto FIG. 7G, the thermal well 5100 includes cuts 5706 on the zone 5406providing flexibility of the zone 5406 for assembly with the fluid line5108. An O-ring 5702 is also provided. Although two cuts are shown, agreater number or fewer cuts are used in alternate embodiments.

Referring now to FIG. 7H, the embodiment shown in FIG. 7F is shown withthe addition of an O-ring 5702. Referring to FIG. 7I, the thermal well5100 is shown insert molded in the fluid line 5108. Zone 5406 is formedto facilitate or enable assembly by insert molding.

FIG. 7J shows an embodiment where the thermal well 5100 is heat staked5708 to retain the thermal well 5100 in the fluid line 5108. In someembodiments of FIG. 7J, an O-ring 5710 is also included. In thisembodiment, the O-ring 5710 has a rectangular cross section. However, inalternate embodiments, the O-ring may have a round or X-shaped crosssection. Likewise, in the various embodiments described herein having anO-ring, the O-ring in those embodiments can have a round, rectangular orX-shaped cross section, or any cross sectional shape desired.

Referring now to FIG. 7K, the thermal well 5100 is retained in the fluidline 5108 by adhesive 5712. The adhesive can be any adhesive, but in oneembodiment, the adhesive is a UV curing adhesive. In alternateembodiments, the adhesive may be any adhesive that is compatible withthe subject media. In this embodiment, the thermal well 5100 is shownwithout a zone 5406.

Referring now to FIG. 7L, thermal well 5100 is shown ultrasonicallywelded in the fluid line 5108. The zone 5406 is fabricated to enablejoining by ultrasonic welding.

Referring now to FIG. 7M, a thermal well 5100 is shown insert molded inthe fluid line 5108. Zone 5406 is a flange for the plastic in the fluidline 5108 to flow around. In the embodiment shown, the flange is flat,however, in other embodiments; the flange may be bell shaped orotherwise.

Referring now to FIG. 7N, the thermal well 5100 is shown retained in thefluid line 5108 by a retaining plate 5714 and a fastener 5716. O-ring5702 is also shown.

Referring now to FIGS. 7O-7P, an end view is shown of a thermal well5100 that is retained in a fluid line 5108 by a retaining ring 5718(FIG. 7O) or in an alternate embodiment, a clip 5720 (FIG. 7P). O-ring5702 is also shown.

Referring now to FIG. 7Q, the embodiment of FIG. 7C is shown with analternate embodiment of the thermal well 5100. In this embodiment of thethermal well 5100 the referred to as zone 5404 in FIG. 4 includes ataper that may allow for easier alignment with a sensing probe, betterisolation of zone 5402 from the ambient and better flow characteristicsin the fluid path. The thermal well 5100 is shown retained in the fluidline 5108 using flexible tabs 5704. An O-ring is also provided.

FIG. 7R shows the embodiment of FIG. 7J with an alternate embodiment ofthe thermal well 5100. The thermal well 5100 shown in this embodimenthas a taper in zone 5404 that may allow for easier alignment with asensing probe, may allow better isolation of zone 5402 from the ambientand may allow better flow characteristics in the fluid path. Zone 5402provides a hemispherical contact for effective thermal coupling with athermal probe. The thermal well 5100 is heat staked 5708 to retain thethermal well 5100 in the fluid line 5108. In some embodiments of FIG.7R, an O-ring 5710 is also included. In this embodiment, the O-ring 5710has a rectangular cross section. However, in alternate embodiments, theO-ring can have a round or X-shaped cross section.

Referring now to FIG. 7S, the embodiment of FIG. 7H is shown with analternate embodiment of the thermal well 5100. FIG. 7S is shown with theaddition of an O-ring 5702. In this embodiment of the thermal well 5100zone 5404 (as shown in FIG. 4) has convolutions that may allow betterisolation of zone 5402 from the ambient. While several geometries havebeen shown for zone 5404, many others could be shown to achieve desiredperformance characteristics.

2. Sensing Probes

Various embodiments of systems, devices, and methods for sensorinterface, including direct sensor contact, sensor interface through theuse of a thermal well, or otherwise with various disposable and reusablecomponents are described. Such systems, devices, and methods for sensorinterface can be used with a wide variety of sensors and in a widevariety of applications. Such systems, devices, and methods for sensorinterface are by no means limited to use with the various sensorembodiments or for use in any particular context.

Referring now to FIG. 8, a sectional view of an exemplary embodiment ofa sensing probe 5800 is shown. The housing 5804 is a hollow structurethat attaches to the tip 5802. The tip is made of a highly thermallyconductive material. The housing 5804, in the exemplary embodiment, ismade from a thermally insulative material. In some embodiments, thehousing is made of a thermally and electrically insulative material. Inthe exemplary embodiment, the housing 5804 is made of plastic which is athermally insulative and electrically insulative material. The tip 5802either contacts the subject media directly, or else is mated with athermal well.

In the exemplary embodiment, the tip 5802 is attached to the housing5804 using a urethane resin or another thermal insulator in between(area 5807) the tip 5802 and the housing 5804. Urethane resinadditionally adds structural support. In alternate embodiments, otherfabrication and joining methods can be used to join the tip 5802 to thehousing 5804.

The tip 5802 of the sensing probe 5800 is made of a thermally conductivematerial. The better thermally conductive materials, for example,copper, silver and steel, can be used, however, depending on the desireduse for the sensing probe and the subject media; the materials may beselected to be durable and compatible for the intended use.Additionally, factors such as cost and ease of manufacture may dictate adifferent material selection. In one exemplary embodiment, the tip 5802is made from copper. In other embodiments, the material can be an alloyof copper or silver, or either solid or an alloy of any thermallyconductive material or element, including but not limited to metals andceramics. However, in the exemplary embodiments, the tip 5802 is madefrom metal.

In the exemplary embodiment, the tip 5802 is shaped to couple thermallywith a thermal well as described in the exemplary embodiment of thethermal well above. In the exemplary embodiment as well as in otherembodiments, the tip 5802 may be shaped to insulate the thermal sensor5808 from the ambient. In the exemplary embodiment, the tip 5802 is madefrom metal.

In alternate embodiments a non-electrically conductive material is usedfor the tip. These embodiments may be preferred for use where it isnecessary to electrically insulate the thermal well from the probe. Inanother alternate embodiment, the tip 5802 may be made from anythermally conductive ceramic.

In the exemplary embodiment, the thermal sensor 5808 is located in thehousing and is attached to the interior of the tip 5802 with a thermallyconductive epoxy 5812. In the exemplary embodiment, the epoxy used isTHERMALBOND, however, in other embodiments; any thermal grade epoxy canbe used. However, in alternate embodiments, thermal grease may be used.In alternate embodiments, an epoxy or grease is not used.

The thermal sensor 5808, in the exemplary embodiment, is a thermistor.The thermistor generally is a highly accurate embodiment. However inalternate embodiments, the thermal sensor 5808 can be a thermocouple orany other temperature sensing device. The choice of thermal sensor 5808may again relate to the intended use of the sensing apparatus.

Leads 5814 from the thermal sensor 5808 exit the back of the housing5804. These leads 5814 attach to other equipment used for calculations.In the exemplary embodiment, a third lead 5816 from the tip 5802 is alsoincluded. This third lead 5816 is attached to the tip on a tab 5818. Thethird lead 5816 is attached to the tip 5802 because in this embodiment,the tip 5802 is metal and the housing is plastic. In alternateembodiments, the housing 5804 is metal, thus the third lead 5816 may beattached to the housing 5804. Thus, the tip 5802, in the exemplaryembodiment, includes a tab 5818 for attachment to a lead. However, inalternate embodiments, and perhaps depending on the intended use of thesensing apparatus, the third lead 5816 may not be included. Also, inalternate embodiments where a third lead is not desired, the tip 5802may not include the tab 5818. Referring now to FIG. 9, an exploded viewof the sensing probe 5800 is shown.

Referring now to FIG. 10 an alternate embodiment of the exemplaryembodiment is shown. In this embodiment, the tip 6002 of the sensingprobe is shown. The tip 6002 includes a zone 6004 that will contacteither a subject media to be tested or a thermal well. A zone 6006attaches to the sensor probe housing (not shown). An interior area 6008accommodates the thermal sensor (not shown). In this embodiment, the tip6002 is made from stainless steel. However, in other embodiments, thetip 6002 can be made from any thermally conductive material, includingbut not limited to: metals (including copper, silver, steel andstainless steel), ceramics or plastics.

In the exemplary embodiment, zone 6006 includes a tab 6010. A third lead(as described with respect to FIG. 8, 5816) attaches from the tab 6010.Referring next to FIGS. 11A and 11B, the sensing probe 6000 is shownincluding the tip 6002 and the housing 6012. In one embodiment, thehousing 6012 is made from any thermally insulative material, includingbut not limited to, plastic. In one embodiment, the housing 6012 ispress fit to the tip 6002, glued or attached by any other method. In oneembodiment, the thermal sensor 6014 is thermally coupled to the tip 6002with thermal grade epoxy or, in alternate embodiments, thermal grease6022. Two leads 6016 from the thermal sensor 6014 extend to the distalend of the housing. In some embodiments, a third lead 6018 is attachedto the tip 6002 from the tab 6010. As discussed above, in someembodiments where the third lead is not desired, the tip 6002 does notinclude a tab 6010.

Referring now to FIG. 11B, an alternate embodiment of the sensing probe6000 is shown. In this embodiment, the housing 6012 is a plastic moldedover zone 6006 of the tip 6002 and the leads 6016, and in someembodiments, a third lead 6018.

Referring now to FIG. 12, a full side view of one embodiment of thesensing probe 6000 shown in FIGS. 10-11B is shown. The sensing probe6000 includes a housing 6012, a tip 6002 and the leads 6016, 6018.Flange 6020 is shown. In some embodiment, flange 6020 is used to mountand/or attachment to equipment.

Referring now to FIG. 13A, the sensing probe 6000 shown in FIGS. 10-12,is shown coupled to a thermal well 5100 which is fastened into a fluidline 5108. In the embodiment as shown, two leads 6016 are shown at thedistal end of the sensing probe 6000. And, in some embodiments, a thirdlead 6018 is also incorporated into the sensing probe 6000. FIG. 13Bshows an alternate embodiment where the sensing probe 6000 includes twoleads 6016 but does not include the third lead 6018.

Referring now to both FIGS. 13A and 13B, the tip 6002 of the sensingprobe 6000 is in direct contact with the thermal well 5100. Referringback to FIG. 4 and still referring to FIGS. 13A and 13B the thermal well5100 includes a zone 5402. The thermal well 5100 is hollow, and theinner part of zone 5402 is formed such that it will be in mating contactwith the sensing probe tip 6002. As shown in this embodiment, thethermal well 5100 is designed to have a mating geometry with the sensingprobe 6000. Thus, the geometry of the thermal well 5100 may depend onthe geometry of the tip 6002 of the sensing probe 6000 and vice-versa.In some embodiments, it may be desirable that the sensing probe 6000does not have a tight fit or a perfect mate with the thermal well 5100.

Referring now to FIG. 14A, one embodiment of the sensing probe 5800 (asshown in FIG. 8) is shown coupled to a thermal well 5100 which isfastened into a fluid line 5108. In the embodiment as shown, two leads5814 are shown at the distal end of the sensing probe 5800. In someembodiments, a third lead 5816 is also incorporated into the sensingprobe 5800. FIG. 14B shows an alternate embodiment where the sensingprobe 5800 includes two leads 5814 but does not include the third lead5816.

Referring now to both FIGS. 14A and 14B, the tip 5802 of the sensingprobe 5800 is in direct contact with the thermal well 5100. Referringback to FIG. 4 and still referring to FIGS. 14A and 14B, the thermalwell 5100 includes a zone 5402. The thermal well 5100 is hollow, and theinner part of zone 5402 is formed such that it will be in mating contactwith the sensing probe tip 5802. As shown in this embodiment, thethermal well 5100 is designed to have a mating geometry with the sensingprobe 5800. Thus, the geometry of the thermal well 5100 depends on thegeometry of the tip 5802 of the sensing probe 5800 and vice-versa.

3. Sensor Apparatus and Sensor Apparatus Systems

3.1 Sensor Apparatus and Sensor Apparatus Systems Utilized in Connectionwith a Fluid Line

For purposes of description of the sensor apparatus, the sensorapparatus is described with respect to exemplary embodiments. Theexemplary embodiments are shown in FIGS. 13A, 13B, and FIG. 15, withalternate exemplary embodiments in 14A and 14B. In alternate embodimentsof the sensor apparatus, the sensing probe can be used outside of thethermal well. However, the sensor apparatus has already been describedherein alone. Thus, the description that follows describes oneembodiment of the exemplary embodiment of the sensor apparatus whichincludes, for this purpose, a sensing probe and a thermal well.

Referring now to FIG. 15, in an exemplary embodiment, the sensing probe6000 shown in FIG. 13A and the thermal well 5100 are shown coupled andoutside of a fluid line. As described above, the thermal well 5100 canbe in a fluid line, a protective sleeve, any disposable, machine,chamber, cassette or container. However, for purposes of thisdescription of the exemplary embodiment, the thermal well 5100 is takento be anywhere where it is used to determine thermal and/or conductiveproperties (FIG. 13A) of a subject media.

A subject media is in contact with the outside of zone 5402 of thethermal well 5100. Thermal energy is transferred from the subject mediato the thermal well 5100 and further transferred to the tip 6002 of thesensing probe 6000. Thermal energy is then conducted to the thermalsensor 6014. The thermal sensor 6014 communicates via leads 6016 withequipment that can determine the temperature of the subject media basedon feedback of the thermal sensor 6014. In embodiments whereconductivity sensing is also desired, lead 6018 communicates withequipment that can determine the conductivity of the subject media. Withrespect to determining the conductivity of the subject media, inaddition to the lead 6018, a second electrical lead/contact (not shown)would also be used. The second lead could be a second sensor apparatusas shown in FIG. 15, or, alternatively, a second probe that is notnecessarily the same as the sensor apparatus shown in FIG. 15, butrather, any probe or apparatus capable of sensing capacitance of thesubject media, including, an electrical contact.

Heat transfer from the tip 6002 to the thermal sensor 6014 may beimproved by die use of a thermal epoxy or thermal grease 6022.

Referring now to FIGS. 14A and 14B, in the alternate exemplaryembodiment, whilst the sensing probe 5800 is coupled to the thermal well5100, the tip 5802, having the geometry shown, forms an air gap 6402between the inner zones 5404 and 5406 of the thermal well 5100 and thetip 5802. The air gap 6402 provides an insulative barrier so that onlythe top of the sensing tip of 5802 is in communication with the top zone5402 of the thermal well 5100.

The sensing probe 5800 and thermal well 5100 are shown coupled andoutside of a fluid line. As described above, the thermal well 5100 canbe in a fluid line, a protective sleeve, disposable unit, machine,non-disposable unit, chamber, cassette or container. However, forpurposes of this description of the exemplary embodiment, the thermalwell 5100 is taken to be anywhere where it is used to determine thermaland/or conductive properties (FIG. 14A) of a subject media.

A subject media is in contact with the outside of zone 5402 of thethermal well 5100. Thermal energy is transferred from the subject mediato the thermal well 5100 and further transferred to the tip 5802 of thesensing probe 5800. Thermal energy is then conducted to the thermalsensor 5808. The thermal sensor 5808 communicates via leads 5814 withequipment that can determine the temperature of the subject media basedon feedback of the thermal sensor 5808. In embodiments whereconductivity sensing is also desired, lead 5816 communicates withequipment that can determine the conductivity of the subject media. Withrespect to determining the conductivity of the subject media, inaddition to the lead 5816, a second electrical lead (not shown) wouldalso be used. The second lead could be a second sensor apparatus asshown in FIG. 14A, or, alternatively, a second probe that is notnecessarily the same as the sensor apparatus shown in FIG. 14A, butrather, any probe or apparatus capable of sensing capacitance of thesubject media, including, an electrical contact.

Heat transfer from the tip 5802 to the thermal sensor 5808 can beimproved by the use of a thermal epoxy or thermal grease 5812.

Referring now to FIG. 16, an alternate embodiment showing a sensingprobe 6602 coupled to a thermal well 5100 is shown. For purposes of thisdescription, any embodiment of the sensing probe 6602 and any embodimentof the thermal well 5100 can be used. In this embodiment, to increasethe thermal coupling between the tip of the sensing probe 6602 and thethermal well 5100, thermal grease 6604 is present at the interface ofthe tip of the sensing probe 6602 and the inner zone 5402 of the thermalwell 5100. In one embodiment, the amount of thermal grease 6604 is avolume sufficient to only be present in zone 5402. However, in alternateembodiments, larger or smaller volumes of thermal grease can be used.

Referring now to FIG. 17, a sensor apparatus system is shown. In thesystem, the sensor apparatus is shown in a device containing a fluidline 5108. The sensor apparatus includes the sensing probe 6000 and thethermal well 5100. In this embodiment, the thermal well 5100 and fluidline 5108 is a disposable portion and the sensing probe 6000 is areusable portion. Also in the reusable portion is a spring 6700. Thespring 6700 and sensing probe 6000 are located in a housing 6708. Thehousing 6708 can be in any machine, container, device or otherwise. Thespring 6700 can be a conical, a coil spring, wave spring, or urethanespring.

In this embodiment, the thermal well 5100 and the sensing probe 6000 mayinclude alignment features 6702, 6704 that aid in the thermal well 5100and sensing probe 6000 being aligned. The correct orientation of thethermal well 5100 and the sensing probe 6000 may aid in the mating ofthe thermal well 5100 and the sensing probe 6000 to occur. Theconfiguration of the space 6706 provides the sensing probe 6000 withspace for lateral movement. This allows the sensing probe 6000 to, ifnecessary; move laterally in order to align with the thermal well 5100for mating.

The sensing probe 6000 is suspended by a spring 6700 supported by theflange 6020. The spring 6700 allow vertical movement of the sensingprobe 6000 when the thermal well 5100 mates with the sensing probe 6000.The spring 6700 aids in establishing full contact of the sensing probe6000 and the thermal well 5100.

The fluid line 5108 can be in any machine, container, device orotherwise. The fluid line 5108 contains a fluid path 5104. A subjectmedia flows through the fluid path 5104 and the thermal well 5100,located in the fluid line 5108 such that the thermal well 5100 has amplecontact with the fluid path 5104 and can sense the temperatureproperties and, in some embodiments, the conductive properties of thesubject media. The location of the thermal well 5100 in the fluid path5104, as described in more detail above, may be related to the desiredaccuracy, the subject media and other considerations.

The spring 6700 and sensing probe 6000 assembly, together with the space6706 in the housing 6708 may aid in alignment for the mating of thesensing probe 6000 and the thermal well 5100. The mating provides thethermal contact so that the thermal well 5100 and the sensing probe 6000are thermally coupled.

A wire 6710 is shown. The wire contains the leads. In some embodiments,there are two leads. Some of these embodiments are temperature sensing.In other embodiments, the wire contains three or more leads. Some ofthese embodiments are for temperature and conductivity sensing.

Referring now to FIG. 18, an alternate embodiment of the system shown inFIG. 17 is shown. In this embodiment, the sensing probe 6000 issuspended by a coil spring 6800. A retaining plate 6802 captures thecoil spring 6800 to retain the spring 6800 and sensing probe 6000. Inone embodiment, the retaining plate 6802 is attached to the housing 6708using screws. However, in alternate embodiments, the retaining plate6802 is attached to the housing 6708 using any fastening methodincluding but not limited to: adhesive, flexible tabs, press fit, andultrasonic welding. Aligning features 6806 on the housing 6708 aid inalignment of the sensing probe 6000 to a thermal well (not shown).Lateral movement of the sensing probe 6000 is provided for by clearancein areas 6808 in the housing 6708. A wire 6710 is shown. The wirecontains the leads. In some embodiments, there are two leads. Some ofthese embodiments are temperature sensing. In other embodiments, thewire contains three or more leads. Some of these embodiments are fortemperature and conductivity sensing.

Referring now to FIG. 19, a sensing probe 6000 is shown in a housing6708. In these embodiments, an alternate embodiment of a spring, aflexible member 6900, is integrated with the sensing probe 6000 to allowvertical movement of the sensing probe 6000 within the housing 6708. Aretaining plate 6902 captures the flexible member 6900 to retain theflexible member 6900 and sensing probe 6000. In one embodiment, theretaining plate 6902 is attached to the housing 6708 using screws.However, in alternate embodiments, the retaining plate 6902 is attachedto the housing 6708 using any fastening method including but not limitedto: adhesive, flexible tabs, press fit, and ultrasonic welding. Lateralmovement of the sensing probe 6000 is provided for by clearance in areas6908 in the housing 6708. A wire 6710 is shown. The wire contains theleads. In some embodiments, there are two leads. Some of theseembodiments are temperature sensing. In other embodiments, the wirecontains three or more leads. Some of these embodiments are fortemperature and conductivity sensing.

Referring now to FIG. 20, an alternate embodiment of a sensing probe6000 in a housing 7002 is shown. In this embodiment, flexible member7000 is attached or part of the housing 7002, provides for verticalmovement of the sensing probe 6000. In this embodiment, the openings7004, 7006 in housing 7002 are sized such that the sensing probe 6000experiences limited lateral movement. Flexible member 7000 acts on theflange 7008 on the sensing probe 6000. A wire 6710 is shown. The wirecontains the leads. In some embodiments, there are two leads. Some ofthese embodiments are temperature sensing. In other embodiments, thewire contains three or more leads. Some of these embodiments are fortemperature and conductivity sensing.

The flange, as shown and described with respect to FIGS. 12, 17, 20, canbe located in any area desired on the sensing probe 6000. In otherembodiments, the sensing probe may be aligned and positioned by otherhousing configurations. Thus, the embodiments of the housing shownherein are only some embodiments of housings in which the sensorapparatus can be used. The sensor apparatus generally depends on beinglocated amply with respect to the subject media. The configurations thataccomplish this can vary depending on the subject media and the intendeduse of the sensing apparatus. Further, in some embodiments where thethermal well is not used, but rather, the sensing probe is used only.The housing configurations may vary as well.

The sensing apparatus, in some embodiments, is used to senseconductivity. In some embodiments, this is in addition to temperaturesensing. In those embodiments where both temperature and conductivitysensing is desired, the sensing probe typically includes at least threeleads, where two of these leads may be used for temperature sensing andthe third used for conductivity sensing.

Referring now to FIG. 21, for conductivity sensing, at least two sensors7102, 7104 are located in an area containing the subject media. In theembodiment shown, the area containing the subject media is a fluid path5104 inside a fluid line 5108. The conductivity sensors 7102, 7104 canbe one of the various embodiments of sensing probes as described above,or one of the embodiments of the sensor apparatus embodiments (includingthe thermal well) as described above. However, in other embodiments,only one of the sensors is one of the embodiments of the sensorapparatus or one of the embodiments of the sensing probe, and the secondsensor is any electrical sensor known in the art. Thus, in the systemsdescribed herein, conductivity and temperature can be sensed throughusing either one of the sensor apparatus or one of the sensor probes asdescribed herein and a second capacitance sensor, or one of the sensorapparatus or one of the sensor probes as described herein and anelectrical sensor.

Referring now to FIG. 22, an alternate embodiment of a sensor apparatusincluding a sensing probe 7200 and a thermal well 5100 is shown in afluid line 5108. In this embodiment, the sensing probe 7200 isconstructed of a metal housing. The thermal well 5100 is alsoconstructed of metal. The thermal well 5100 and the sensing probe 7200can be made from the same metal or a different metal. The metal, in thepreferred embodiment, is a conductive metal, which may include stainlesssteel, steel, copper and silver. A lead 7202 is attached to the sensingprobe 7200 housing for conductivity sensing. The thermal sensing leads7204 are attached to a thermal sensor located inside the sensing probe7200 housing. In this embodiment, therefore, the third lead 7202 (or thelead for conductivity sensing) can be attached anywhere on the sensingprobe 7200 because the sensing probe 7200 is constructed of metal. Inthe previously described embodiments, where the sensing probe housingwas constructed of plastic, and the sensing tip constructed of metal,the third lead for conductivity sensing was attached to the sensing tip.

A known volume of subject media may be used to determine conductivity.Thus, two sensors may be used and the volume of fluid between the twosensors can be determined. Conductivity sensing is done with the twoelectrical contacts (as described above), where one or both can be thesensor apparatus. The volume of subject media between the two contactsis known.

Conductivity sensing is done by determining the conductivity from eachof the sensors and then determining the difference. If the difference isabove a predetermined threshold, indicating an abnormal difference inconductivity between the first and second sensor (the designations“first” and “second” being arbitrary), then it can be inferred that airmay be trapped in the subject media and a bubble detection alarm may begenerated to indicate a bubble. Thus, if there is a large decrease inconductivity (and likewise, a large increase in resistance) between thefirst and second sensor, air could be trapped and bubble presence may bedetected.

Leaks in a machine, system, device or container may be determined usingthe conductivity sensing. Where a sensing apparatus is in a machine,device or system, and that sensing apparatus senses conductivity, in oneembodiment, a lead from the sensor apparatus (or electrical contacts) toan analyzer or computer machine may be present.

In some embodiments, the analyzer that analyzes the electrical signalsbetween the contacts is connected to the metal of the machine, device,system or container. If the analyzer senses an electrical signal fromthe machine, then a fluid leak may be inferred.

3.2. Sensor Apparatus and Sensor Apparatus Systems Utilized inConnection with a Fluid Cassette

The cassette embodiments shown and described in this description includeexemplary and some alternate embodiments. However, any variety ofcassettes are contemplated that include similar or additionalfunctionality. As well, the cassettes may have varying fluid pathsand/or valve placement and may utilize pumping functions, valvingfunctions, and/or other cassette functions. All of these embodiments arewithin the scope of the invention.

3.2.1. Flexible Membrane Fluid Cassette

Fluid cassettes, including flexible membrane fluid cassettes of thetypes described in U.S. Pat. Nos. 5,350,357 issued Sep. 27, 1994 andentitled Peritoneal Dialysis Systems And Methods Employing A LiquidDistribution And Pumping Cassette That Emulates Gravity Flow; 5,755,683issued May 26, 1998 and entitled Cassette For Intravenous-LineFlow-Control System; 6,223,130 issued Apr. 24, 2001 entitled ApparatusAnd Method For Detection Of A Leak In A Membrane Of A Fluid Flow ControlSystem; 6,234,997 issued May 22, 2001 entitled System And Method ForMixing And Delivering Intravenous Drugs; 6,905,479 issued Jun. 14, 2005entitled Pumping Cartridge Having An Integrated Filter And Method ForFiltering A Fluid With The Cartridge; and U.S. patent application Ser.Nos. 10/412,658 filed Apr. 10, 2003 entitled System And Method ForDelivering A Target Volume Of Fluid; and 10/696,990 filed Oct. 30, 2003entitled Pump Cassette Bank, all of which are hereby incorporated hereinby reference in their entireties, may be used in conjunction with thesensor apparatus and sensor apparatus systems described herein.

FIGS. 23A-C show an exemplary embodiment of a flexible membrane cassetteof a similar type to those generally disclosed in U.S. Pat. No.5,350,357 and other of the patents and patent applications referencedabove. FIGS. 23A-C shows back, side, and front views of exemplarycassette 2300. As FIGS. 23A-C show, the cassette 2300 includes aninjection molded body having back side 2310 shown in FIG. 23A and frontside 2311 shown in FIG. 23C. A flexible diaphragm (one of which is shownas 59 in FIG. 24) overlies the front side and back side of cassette2300.

The cassette 2300 is preferably made of a rigid plastic material and thediaphragms are preferably made of flexible sheets of plastic, althoughmany other materials may be utilized.

Exemplary cassette 2300 forms an array of interior cavities in theshapes of wells and channels. In exemplary cassette 2300, the interiorcavities create multiple paths, such as fluid path 2303, to conveyliquid (as FIG. 23A shows). In exemplary cassette 2300, the interiorcavities also create pump chambers, such as pump chambers 2301 and 2302(as FIG. 23C shows) and multiple valve stations, such as valve station2304 (as FIG. 23C shows). In the exemplary cassette 2300, the valvestations, such as valve station 2304, interconnect the multiple liquidpaths, such as fluid path 2303, with pump chambers 2301 and 2302 andwith each other.

In certain embodiments, exemplary cassette 2300 may be utilized inconjunction with a device (not shown) that locally applies positive andnegative pressure, including positive and negative fluid pressure of thetype described in U.S. Pat. No. 5,350,357 and other of the patents andpatent applications referenced above, on the diaphragm regions overlyingthe valve stations and pump chambers. While many different types of pumpchambers and valves may be utilized with cassette of the types describedherein (or, in certain embodiments, not included at all), exemplary pumpchambers and valve stations of the type shown in FIGS. 23A-C aredescribed in more detail in U.S. Pat. No. 5,350,357, incorporatedherein. The presence, number, and arrangement of the pump chambers,liquid paths, and valve stations can vary. Additionally, alternative oradditional cassette functionality may be present in a given cassette.

With further reference to FIGS. 23A-C, exemplary cassette 2300 includessensor ports 2305 and 2306 that extend into fluid path 2303. Sensorports 2305 and 2306 may be used to insert a sensing probe, thermal wellor other sensing element to allow. Exemplary cassette 2300 shows twosensor ports per cassette, but one port, two ports, or more than twoports may be used depending on the configuration of the cassette and thetype of sensor or sensors used.

Again, with reference to FIG. 23A-C, exemplary cassette 2300 is shownwith sensor ports 2305 and 2306 position in the rigid body of cassette2300. In the case of a rigid cassette body with two flexible membranes,one on either side of the rigid body, as shown in FIG. 23A-C, in oneembodiment sensor ports 2305 and 2306 may be position in the rigid bodyportion of the cassette (as shown best in FIG. 23B). However, in otherembodiments, the sensor port may extend though one or more areas of theflexible diaphragm overlying the cassette.

Referring now to FIG. 24, exemplary cassette 2300 is shown with sensorports 2305 and 2306 extending into fluid path 2303 such that a componentplaced in sensor ports 2305 and 2306 would come into direct contact withthe subject media contained in or flowing through fluid path 2303. FIG.24 additionally shows thermal wells 5100 positioned near sensor ports2305 and 2306. In this embodiment, cassette 2300 and thermal wells 5100are separate parts. In some embodiments, the cassette 2300 and thethermal well 5100 are made from different materials. For theseembodiments, the thermal well 5100 can be made from any materials,including but not limited to, plastic, metal, ceramic or a combinationthereof. The material may depend in some part on the compatibility withthe intended subject media. In other embodiments, thermal well 5100could be made from the same material as cassette 2300. In yet furtherembodiments, thermal well 5100 could be formed as a part of thestructure of the rigid body of cassette 2300.

The length and width of the thermal well 5100 utilized with exemplarycassette 2300 can be any length and width having the desired ortolerable accuracy characteristics and which properly positions anysensor or sensing probe utilized with thermal well 5100 sufficiently incontact with the subject media contained in or flowing through fluidpath 2306. The length of thermal well 5100 may impact the fluid flow ofthe subject media in fluid path 2303 to a certain extent. It also shouldbe understood that the length of the thermal well 5100 may also impactthe turbulence of the fluid flow. Thus, the length and width of thethermal well 5100 may be changed to have greater or lesser impact on thefluid flow and turbulence of the fluid, while mitigating the othervariables.

The shape of the thermal well 5100 is also a variable. Any shape desiredis contemplated. However, the shape of the thermal well 5100, as withthe other variables, is determined in part based on the intended use ofthe sensor apparatus. For purposes of description, an exemplaryembodiment is described herein. However, the shape in the exemplaryembodiment is not meant to be limiting. All of the various embodimentsof thermal wells described herein may be used in conjunction withcassettes, such as exemplary cassette 2300.

FIG. 25 shows thermal wells 5100 installed in exemplary cassette 2300.Thermal well 5100 may be installed in exemplary cassette 2300 by use ofthe ways described herein, including adhesive, welding (ultrasonic andotherwise), o-ring, retaining plate, and otherwise. The thermal well5100 used in connection with a cassette may be of various shapes andconfigurations. However, referring now to FIG. 4 for purposes ofdescription, the embodiment of a thermal well 5100 shown may be utilizedin conjunction with a cassette. In the exemplary embodiment shown inFIG. 4, the bottom zone 5406 is shaped to aid in press fitting thethermal well into the sensor port 2305 shown in FIGS. 23A-C and 24.

FIG. 26 further shows thermal well 5100 installed in sensor port 2305and 2306. As may be best shown by FIG. 27, thermal well 5100 extendsinto fluid path 2303 so that thermal well 5100 may come into directcontact with any subject media contained in or flowing through exemplarycassette 2300.

In certain embodiments of sensor apparatus and sensor apparatus systemsused in conjunction with a flexible membrane cassette, a sensing probemay be installed directly into sensing ports 2305 and 2306 (sensingports 2305 and 2306 as shown in FIGS. 23A-C and 24). In furtherembodiments of sensor apparatus and sensor apparatus systems used inconjunction with a flexible membrane, a sensing probe may be used with athermal well.

As can be seen in FIG. 27, subject media is in contact with the outsideof zone 5402 of the thermal well 5100. Thermal energy is transferredfrom the subject media to the thermal well 5100. As may be seen withreference to FIG. 13A-B, the thermal energy can then be furthertransferred to the tip 6002 of the sensing probe 6000. Thermal energy isthen conducted to the thermal sensor 6014. The thermal sensor 6014communicates via leads 6016 with equipment that can determine thetemperature of the subject media based on feedback of the thermal sensor6014. In embodiments where conductivity sensing is also desired, lead6018 communicates with equipment that can determine the conductivity ofthe subject media. With respect to determining the conductivity of thesubject media, in addition to the lead 6018, a second electricallead/contact (not shown) would also be used. The second lead could beany probe or apparatus capable of sensing capacitance of the subjectmedia, including, an electrical contact.

Heat transfer from the tip 6002 to the thermal sensor 6014 may beimproved by the use of a thermal epoxy or thermal grease 6022.

Many different embodiments of sensing apparatus may be used inconnection with a thermal well installed in a flexible cassette,including embodiments similar to those shown in FIGS. 14A-B, 15, and 16,and described above.

While several geometries have been described, many others could be shownto achieve desired performance characteristics.

In certain embodiments, exemplary cassette 2300 may be utilized inconjunction with a device (not shown) that locally applies positive andnegative pressure, including positive and negative fluid pressure of thetype described in U.S. Pat. No. 5,350,357 and other of the patents andpatent applications referenced above, on the diaphragm regions overlyingthe valve stations and pump chambers. When cassette 2300 is utilized inconjunction with a pressure applying device (not shown), cassette 2300may be connected to the device in a number of different ways and in anumber of different positions. Preferably, in certain embodiments,cassette 2300 may be loaded in a device in other than a horizontalorientation, such as a vertical or substantially vertical orientation.Placement of the cassette in a vertical or substantially verticalorientation may offer certain advantages depending on the configurationof the cassette such as to avoid air entrapment and to optimizeapplication of positive and negative pressure, including positive andnegative fluid pressure of the type described in U.S. Pat. No. 5,350,357and other of the patents and patent applications referenced above, tothe cassette.

Referring now to FIG. 28, a sensor apparatus system of the typegenerally shown may be used in connection with exemplary cassette 2300.In the system, the sensor apparatus is installed in sensor ports 2305and 2305 (not shown) extending into fluid path 2303. The sensorapparatus includes the sensing probe 6000 and the thermal well 5100. Inthis embodiment, the thermal well 5100 and fluid line 2303 is containedin an exemplary cassette 2300. In certain embodiments, exemplarycassette 2300 is intended to be disposable. Sensing probe 6000 ismounted in a reusable portion. Also in the reusable portion is a spring2801. The spring 2801 and sensing probe 6000 are located in a housing2800. The housing 2800 can be in any machine, container, device orotherwise. In certain embodiments the reusable portion in contained inor otherwise a part of a pressure applying device (as described above).The spring 2801 can be a conical, a coil spring, wave spring, orurethane spring.

In certain embodiments, the thermal well 5100 and the sensing probe 6000may include alignment features (of the type shown in FIG. 17, 6702,6704) that aid in the thermal well 5100 and sensing probe 6000 beingaligned. The correct orientation of the thermal well 5100 and thesensing probe 6000 may aid in the mating of the thermal well 5100 andthe sensing probe 6000 to occur. Referring again to FIG. 28, theconfiguration of the housing 2800 may provide the sensing probe 6000with space for lateral movement. This allows the sensing probe 6000 to,if necessary; move laterally in order to align with the thermal well5100 for mating.

In various embodiments, the sensing probe 6000 is configured withrespect to the housing 2800 (as shown in FIG. 28) to facilitateengagement between the sensing probe 6000 and the thermal well 5100 andto aid in establishing full contact of the sensing probe 6000 and thethermal well 5100. Variations of the configurations generally shown inFIGS. 18-20 and described above may be used in conjunction withexemplary cassette 2300.

In other embodiments, the sensing probe may be aligned and positioned byother housing configurations. Thus, the embodiments of the housing shownherein are only some embodiments of housings in which the sensorapparatus can be used. The sensor apparatus generally depends on beinglocated amply with respect to the subject media. The configurations thataccomplish this can vary depending on the subject media and the intendeduse of the sensing apparatus. Further, in some embodiments where thethermal well is not used, but rather, the sensing probe is used only.The housing configurations may vary as well.

In embodiments in which cassette 2300 is loaded into a device, such as apressure applying device, in a vertical or substantially verticalorientation, it may be preferable for sensor ports 2305 and 2306 to bepositioned in the bottom edge of cassette 2300 (the bottom edge as thecassette is shown in FIG. 23A). Positioning of the sensor ports 2305 and2306 along the bottom edge of exemplary cassette 2300 (such that sensorports 2305 and 2306 and installed thermal wells 5100 extend into thebottom fluid line 2303 of the cassette) may facilitate engagement withthe sensor apparatus as shown in FIG. 28. In certain of theseembodiments, the exemplary cassette 2300 with installed thermal wells5100 may be placed in position over sensor probes 6000, and then rotatedvertically down and onto the sensor probes 6000.

The sensing apparatus, in some embodiments, is used to senseconductivity of the subject media within a fluid line within a cassette.In some embodiments, this is in addition to temperature sensing. Inthose embodiments where both temperature and conductivity sensing isdesired, the sensing probe typically includes at least three leads,where two of these leads may be used for temperature sensing and thethird used for conductivity sensing.

Referring now to FIG. 21, for conductivity sensing, at least two sensors7102, 7104 are located in an area containing the subject media. In theembodiment shown, the area containing the subject media is a fluid path5104 inside a fluid line 5108. The conductivity sensors 7102, 7104 canbe one of the various embodiments of sensing probes as described above,or one of the embodiments of the sensor apparatus embodiments (includingthe thermal well) as described above.

Referring now to FIG. 28, sensing probes 6000 installed in thermal wells5100 in sensor ports 2305 and 2306 can be used for sensing theconductivity of the subject media located between sensor ports 2305 and2306 in fluid line 2303. However, in other embodiments, only one of thesensors is one of the embodiments of the sensor apparatus or one of theembodiments of the sensing probe, and the second sensor is anyelectrical sensor known in the art. Thus, in the systems describedherein, conductivity and temperature can be sensed through using eitherone of the sensor apparatus or one of the sensor probes as describedherein and a second capacitance sensor, or one of the sensor apparatusor one of the sensor probes as described herein and an electricalsensor.

3.2.2 Pod Pump Cassette

Cassettes other than the flexible membrane cassette described above maybe used in conjunction with the sensor apparatus and sensor apparatussystems described herein. Cassette, such as cassettes of the typesdescribed in patent application Ser. No. 11/787,213 entitled HeatExchange Systems, Devices and Methods which was filed on Apr. 13, 2007;patent application Ser. No. 11/787,212 entitled Fluid Pumping Systems,Devices and Methods which was filed on Apr. 13, 2007; and patentapplication Ser. No. 11/787,112 entitled Thermal and ConductivitySensing Systems, Devices and Methods which was filed on Apr. 13, 2007and issued as U.S. Pat. No. 7,794,141 on Sep. 14, 2010, all of which arehereby incorporated herein by reference in their entireties, may be usedin conjunction with the sensor apparatus and sensor apparatus systemsdescribed herein. Additionally, cassettes, cassette assemblies, andmanifolds of the types described in the following applications may beused in conjunction with the sensor apparatus and sensor apparatussystems described herein: U.S. patent application Ser. No. 11/871,680,filed Oct. 12, 2007 entitled Pumping Cassette; U.S. patent applicationSer. No. 11/871,712, filed Oct. 12, 2007 entitled Pumping Cassette; U.S.patent application Ser. No. 11/871,787, filed Oct. 12, 2007 and entitledPumping Cassette; U.S. patent application Ser. No. 11/871,793, filedOct. 12, 2007 and entitled Pumping Cassette; and U.S. patent applicationSer. No. 11/871,803, filed Oct. 12, 2007 and issued as U.S. Pat. No.7,967,022 on Jun. 28, 2011 and entitled Cassette System IntegratedApparatus. Further, a variety of devices, including medical devices,such as the hemodialysis systems and methods of the types described inU.S. patent application Ser. No. 11/871,680, filed Oct. 12, 2007entitled Pumping Cassette; U.S. patent application Ser. No. 12/072,908,filed Feb. 27, 2008 and issued as U.S. Pat. No. 8,246,826 on Aug. 21,2012 and entitled Hemodialysis System and Methods; and U.S. patentapplication Ser. No. 12/038,648, filed Feb. 27, 2008 and issued as U.S.Pat. No. 8,042,563 on Oct. 25, 2011 and entitled Cassette SystemIntegrated Apparatus, all of which are hereby incorporated herein byreference in their entireties.

In an exemplary embodiment of other cassettes used in conjunction withthe sensor apparatus and sensor apparatus systems described herein, thecassette includes a top plate, a midplate and a bottom plate. Ingeneral, the top plate includes pump chambers, and potentiallyalternative or additional features; the midplate includes complementaryfluid lines, metering pumps, valves and potentially alternative oradditional features; and the bottom plate includes actuation chambers.In general, membranes are located between the midplate and the bottomplate; however, many alternative embodiments are possible. In theexemplary embodiment, the cassettes are formed by placing the membranesin their correct locations, assembling the plates in order and laserwelding the plates. The cassettes may be constructed of a variety ofmaterials. Generally, in the various exemplary embodiment, the materialsused are solid and non flexible. In the preferred embodiment, the platesare constructed of polysilicone, but in other embodiments, the cassettesare constructed of any other solid material and in exemplary embodiment,of any thermoplastic.

FIG. 29 is a sectional view of an exemplary pump pod 100 that isincorporated into a fluid control or pump cassette, in accordance withan exemplary embodiment of the cassette. In this embodiment, the pumppod is formed from three rigid pieces, namely a “top” plate 106, amidplate 108, and a “bottom” plate 110 (it should be noted that theterms “top” and “bottom” are relative and are used here for conveniencewith reference to the orientation shown in FIG. 29). The top and bottomplates 106 and 110 include generally hemispheroid portions that whenassembled together define a hemispheroid chamber, which is a pump pod100. A membrane 112 separates the central cavity of the pump pod intotwo chambers.

Referring now to FIGS. 30A-B, in the exemplary embodiment of thecassette, sensors are incorporated into the cassette so as to discernvarious properties of subject media contained in or flowing through thecassette. In various embodiments one sensor may be included to sensetemperature and/or other properties of the subject media. In anotherembodiment, two sensors may be included, to sense temperature and/orconductivity and/or other properties of the subject media. In yetfurther embodiments, three or more sensors may be included. However, inthe exemplary embodiment, 6 sensors (2 sets of 3) are included. Thesensors are located in the sensor block 1314, 1316. In this embodiment,a sensor block 1314, 1316 is included as an area on the cassette for asensor(s). In the exemplary embodiment, the three sensors of the twosensor blocks 1314, 1316 are housed in respective sensor housings 1308,1310, 1312 and 1318, 1320, 1322. In the exemplary embodiment, two of thesensor housings 1308, 1312 and 1318, 1320 accommodate a conductivitysensor and the third sensor housing 1310, 1322 accommodates atemperature sensor. The conductivity sensors and temperature sensor canbe any conductivity or temperature sensor in the art. In one embodiment,the conductivity sensor elements (or sensor leads) are graphite posts.In other embodiments, the conductivity sensors elements are posts madefrom stainless steel, titanium, or any other material of the typetypically used for (or capable of being used for) conductivitymeasurements. In certain embodiments, the conductivity sensors willinclude an electrical connection that transmits signals from the sensorlead to a sensor mechanism, controller or other device. In variousembodiments, the temperature sensor can be any of the temperaturesensors commonly used (or capable of being used) to sense temperature.

However, in alternate embodiments, a combination temperature andconductivity sensor is used of the types described above. In suchalternate embodiments, thermal wells of the types described above may beinstalled in the cassette. In such embodiments, thermal well 5100 may beinstalled in the cassette by use of any of the ways described herein,including adhesive, welding (ultrasonic and otherwise), o-ring,retaining plate, and otherwise.

In alternate embodiments, there are either no sensors in the cassette oronly a temperature sensor, only one or more conductivity sensors or oneor more of another type of sensor.

Referring now to FIGS. 31A-13B, the bottom plate 1300 is shown.Referring first to FIG. 31A, the inner or inside surface of the bottomplate 1300 is shown. The inner or inside surface is the side thatcontacts the bottom surface of the midplate (not shown). The bottomplate 1300 attaches to the air or actuation lines (not shown). Thecorresponding entrance holes for the air that actuates the pod pumps820, 928 and valves (not shown) in the midplate can be seen 1306. Holes810, 824 correspond to the first fluid inlet and first fluid outletshown in FIG. 30B, 810, 824 respectively. The corresponding halves ofthe pod pumps 820, 828 and mixing chamber 818 are also shown, as are theraised fluid paths 1002 for the fluid paths. The actuation holes in thepumps are also shown. Unlike the top plate, the bottom plate 1300corresponding halves of the pod pumps 820, 828 and mixing chamber 818make apparent the difference between the pod pumps 820, 828 and mixingchamber 818. The pod pumps 820, 828 include an air/actuation path on thebottom plate 1300, while the mixing chamber 818 has identicalconstruction to the half in the top plate. The mixing chamber 818 mixesliquid and therefore, does not include a membrane (not shown) nor anair/actuation path. The sensor block 1310, 1316 with the three sensorshousings 1308, 1310, 1312 and 1318, 1320, 1322 are also shown.

Referring now to FIG. 31B, the actuation ports 1306 are shown on theoutside or outer bottom plate 1300. An actuation source is connected tothese actuation ports 1306. Again, the mixing chamber 818 does not havean actuation port as it is not actuated by air. Referring to FIG. 31C, aside view of the exemplary embodiment of the bottom plate 1300 is shown.

Referring next to FIGS. 32A and 32B, the assembled exemplary embodimentof the cassette 1400 is shown. FIGS. 32C and 32D are exploded view ofthe exemplary embodiment of the cassette 1400. One embodiment of theconductivity sensors 1214, 1216 and the temperature sensor 1218, whichmake up the sensor cell 1212, are also shown in FIGS. 32C and 32D. Stillreferring to FIGS. 32C and 32D, the sensors are housed in sensor blocks(shown as 1314, 1316 in FIGS. 30B and 31A) which include areas on thebottom plate 1300 and the midplate 1200. O-rings seal the sensorhousings from the fluid lines located on the upper side of the midplate1200 and the inner side of the top plate 1100. However, in otherembodiments, an o-ring is molded into the sensor block or any othermethod of sealing can be used.

Referring now to FIGS. 33A-33C, various cross sectional views of theassembled cassette are shown. Referring now to FIG. 33B, the twoconductivity sensors 1308, 1312 and the temperature sensor 1310 areshown. As can be seen from the cross section, the sensors 1308, 1310,1312 are in the fluid line 824. Thus, the sensors 1308, 1310, 1312 arein fluid connection with the fluid line and can determine sensor data ofthe fluid exiting fluid outlet one 824. Still referring to FIG. 33B, avalve 826 cross section is shown.

Referring now to FIG. 33C, the two conductivity sensors 1318, 1320 andthe temperature sensor 1322 are shown. As can be seen from the crosssection, the sensors 1318, 1320, 1322 are in the fluid line 824. Thus,the sensors 1318, 1320, 1322 are in fluid connection with the fluid lineand can determine sensor data of the fluid entering the mixing chamber(not shown in this figure).

Thus, in the exemplary embodiment, the sensors 1318, 1320, 1322 are usedto collect data regarding fluid being pumped into the mixing chamber.Referring back to FIG. 30B, sensors 1308, 1310, 1312 are used to collectdata regarding fluid being pumped from the mixing chamber and to thefluid outlet. However, in alternate embodiments, no sensors are or onlyone set, or only one type of sensor (i.e., either temperature orconductivity sensor) is used. Any type of sensor may be used andadditionally, any embodiment of a temperature, a conductivity sensor ora combined temperature/conductivity sensor.

3.3. Sensor Apparatus and Sensor Apparatus Systems Utilized inConnection with a Manifold

FIG. 34 shows a system 10 in accordance with an exemplary embodiment ofthe present invention. System 10 includes a base unit 11 and adisposable unit 16 including a manifold. The disposable unit 16 isconsidered to be “disposable” in that it is generally discarded after apatient treatment, whereas the base unit 11 can be re-used repeatedly bysimply installing a new disposable unit 16.

FIG. 35 shows relevant components of a disposable unit 16, in accordancewith an exemplary embodiment of the present invention. The disposableunit 16 includes, among other things, a manifold 130. The disposableunit 16 preferably also includes a handle (not shown) that is used tomechanically interconnect the above-referenced components into acohesive unit that can be readily installed into the base unit 11, whichpreferably includes a manifold interface (described below) for receivingthe manifold 130 and providing pneumatic and other connections. In thisembodiment, the manifold 130 is integrated with the heat-exchanger bag21 and is configured with appropriate tubing connections and supportsthat are used to interconnect the heat-exchanger bag 21 with the twopump pods 25 a and 25 b. In the embodiment shown in FIG. 35, themanifold 130 includes two flow-path inlets 23 a and 23 b (also referredto as “heat-exchanger bag inlets”) in fluid communication with one endof the fluid path 150 and a flow-path outlet 27 (also referred to as a“heat-exchanger bag outlet”) in fluid communication with the other endof the fluid path 150. In alternative embodiments, manifold 130 may beused in connection with disposable unit 16 that does not include aheat-exchanger bag or other components shown in FIG. 35.

FIGS. 38A and 38B respectively show a perspective back-side view and aperspective bottom view of the manifold 130 from FIG. 35, in accordancewith an exemplary embodiment of the present invention. FIG. 38A showsbag inlet and outlet connectors 2053, 2054 for connection at the inletand outlet openings of the fluid channel 150 of the bag 21. The baginlet connector 2053 is in fluid communication with the inlets 23 a, 23b, while the bag outlet connector 2054 is in fluid communication withthe outlet 27. The thermal wells 133 a and 133 b are shown in the outletfluid path and the inlet fluid path, respectively.

FIG. 36B shows a perspective back-side cross-sectional view of themanifold 130 of FIGS. 35, 38A, and 38B, in accordance with an exemplaryembodiment of the present invention. In this embodiment, the manifold130 includes an inlet thermal well 133 a located in a bag inlet 23 a andan outlet thermal well 133 b located in a bag outlet 27. The thermalwells 133 a, 133 b interface with corresponding probes in a manifoldinterface of the base unit 11 (discussed below) when the disposable unit16 is installed in the base unit 11. FIG. 36C shows a close-up view ofan exemplary thermal well, although all of thermal well embodimentsdescribed herein may be utilized in connection with a manifold, such asmanifold 130.

The thermal wells 133 a, 133 b provide for both thermal and electricalinterconnections between the base unit 11 and the disposable unit 16.Among other things, such thermal and electrical interconnections allowthe controller 49 to monitor blood temperature as the blood enters andexits the heat-exchanger bag 21 and also allow the controller 49 to takeother measurements (e.g., to detect the presence of blood or air in theheat-exchanger bag 21 and to perform leak detection) as discussed below.In this embodiment, each of the thermal wells 133 a, 133 b is coupled soas to have a portion residing directly in the fluid path (i.e., incontact with the blood) so as to permit better transmission of bloodtemperature from the disposable unit 16 to the base unit 11. In lieu of,or in addition to, the thermal wells, the disposable unit 16 may includeother temperature probes/sensors and interfaces by which the controller49 can monitor blood temperature as the blood enters and exits theheat-exchanger bag 21.

While the exemplary embodiment shown in FIGS. 36B, 38A, and 38B includethermal wells for transmitting thermal information to the base unit 11and optionally for use in conductivity sensing, it should be noted thatother types of sensor components may be additionally or alternativelyused. For example, rather than using a thermal well, a sensor componentthat sends temperature measurements or signals to the base unit 11 maybe used. Various types and configurations of sensors are describedbelow. In other embodiments, any of the sensor apparatus and sensorapparatus systems described herein may be used in conjunction with amanifold, such as manifold 130.

FIG. 26 shows a close-up view of the manifold interface 2500 shown inFIG. 25. The manifold interface 2500 includes, among other things,probes 61, 62 and pneumatic ports 2539 a, 2539 b. With reference againto FIG. 13B, it can be seen that the manifold 130 can be installed inthe manifold interface 2500 such that the probes 61, 62 interfacerespectively with the thermal wells 133 a, 133 b and the pneumatic ports2539 a, 2539 b interface respectively with the pneumatic interfaces 139a, 139 b. The manifold interface 2500 also includes a data key interface2540 for interfacing with a corresponding data key in the disposableunit. The data key interface 2540 preferably provides a bi-directionalcommunication interface through which the controller 49 can readinformation from the disposable unit (e.g., serial/model number,expiration date, and prior usage information) and write information tothe disposable unit (e.g., usage information). In an exemplaryembodiment, the controller 49 may prevent the start of a treatment ifthe data key is not present or if the disposable unit is unusable, forexample, because it includes an unacceptable serial/model number, ispast a pre-configured expiration date, or has already been used. Thecontroller 49 may terminate a treatment if the data key is removed. Inlieu of a data key interface 2540, the base unit 11 or manifoldinterface 2500 may include other types of interfaces for readinginformation from the disposable unit and/or writing information to thedisposable unit (e.g., RFID, bar code reader, smart key interface).

It should be noted that one or more pumps (e.g., pump pods) may beintegral with a manifold such as the manifold 130 and placed in a baseunit as a single cartridge. The assembly could include pneumaticconnections from the pneumatic ports (which are connected to the baseunit) directly to the pump actuation chambers so that no external tubingwould be needed to make the pneumatic connections to the pump pods. Theassembly could additionally or alternatively include fluidic connections(e.g., from the pump outlets to the interface with the heat-exchangerbag) so that no external tubing would be needed between the pump outletsand the manifold or bag.

3.4. Sensor Apparatus and Sensor Apparatus Systems Utilized inConnection with a Sensor Manifold

In various embodiments of the inventions described herein, a sensorapparatus systems may be utilized that comprises a sensor manifold. Asensor manifold may allow subject media to be moved from one environmentto another environment that is more conducive to obtaining sensorreadings. For example, the cassette manifold may be contained in an areathat is not subject to various types of environment conditions, such astemperature and/or humidity, which would not be preferable for sensorapparatus such as a sensing probe. Alternatively, sensing apparatus andsensing apparatus system may be delicate and may be probe to greatermalfunctions than other components of a system. Separating the sensorapparatus and the sensor apparatus systems from the remainder of thesystem by use of a sensor manifold may allow the sensing apparatus andsensing apparatus systems to be repaired or replaced with minimal impactto the remainder of the system. Alternative, the sensor manifold may bereplaced either more or less frequently than other components of thesystem.

With reference to FIG. 39, an exemplary sensor manifold is shown. Asubject media may be contained in or flow through cassette 3900. In thisembodiment, cassette 3900 is comprised of a rigid body overlaid by oneor more flexible diaphragms of the types described herein. Pre-moldedtube connector 3901 allows subject media to enter sensor cassette 3900from another source and flow through fluid path 3903. Subject mediaexits the cassette through pre-molded tube connector 3902. While tubeconnectors 3901 and 3902 are shown as pre-molded tube connectors, otherembodiments may use any other fluid transfer devices to allow subjectmedia into fluid path 3903.

With further reference to FIG. 39, cassette manifold 3900 includessensor ports 3904, 3905, and 3906 that extend into fluid path 3903.Sensor ports 3904, 3905, and 3906 may be used to insert a sensing probe,thermal well or other sensing element to allow. Exemplary cassettemanifold 3900 shows three sensor ports per cassette manifold, but anynumber of ports may be used depending on the configuration of thecassette manifold and the type of sensor or sensors used.

Again, with reference to FIG. 39, exemplary cassette manifold 3900 isshown with sensor ports 3904, 3905, and 3906 positioned in the rigidbody of cassette manifold 3900. In the case of a rigid cassette bodywith two flexible membranes, one on either side of the rigid body, asshown in FIG. 39, in one embodiment sensor ports 3904, 3905, and 3906may be position in the rigid body portion of the cassette (as shown inFIG. 39). However, in other embodiments, the sensor port may extendthough one or more areas of the flexible diaphragm overlying thecassette manifold.

Referring again to FIG. 39, exemplary cassette manifold 3900 is shownwith sensor ports 3904, 3905, and 3906 extending into fluid path 3903such that a component placed in sensor ports 3904, 3905, and 3906 wouldcome into direct contact with the subject media contained in or flowingthrough fluid path 3903. FIG. 39 additionally shows thermal wells 5100installed in sensor ports 3904, 3905, and 3906. In certain embodiments,cassette manifold 2300 and thermal wells 5100 are separate parts. Insome embodiments, the cassette manifold 3900 and thermal well 5100 aremade from different materials. For these embodiments, the thermal well5100 can be made from any materials, including but not limited to,plastic, metal, ceramic or a combination thereof. The material maydepend in some part on the compatibility with the intended subjectmedia. In other embodiments, thermal well 5100 could be made from thesame material as cassette manifold 3900. In yet further embodiments,thermal well 5100 could be formed as a part of the structure of therigid body of cassette manifold 3900.

The length and width of thermal well 5100 utilized with exemplarycassette 2300 can be any length and width having the desired ortolerable accuracy characteristics and which properly positions anysensor or sensing probe utilized with thermal well 5100 sufficiently incontact with the subject media contained in or flowing through fluidpath 2306. The length of thermal well 5100 may impact the fluid flow ofthe subject media in fluid path 2303 to a certain extent. It also shouldbe understood that the length of the thermal well 5100 may also impactthe turbulence of the fluid flow. Thus, the length and width of thethermal well 5100 may be changed to have greater or lesser impact on thefluid flow and turbulence of the fluid, while mitigating the othervariables.

The shape of the thermal well 5100 is also a variable. Any shape desiredis contemplated. However, the shape of the thermal well 5100, as withthe other variables, is determined in part based on the intended use ofthe sensor apparatus. For purposes of description, an exemplaryembodiment is described herein. However, the shape in the exemplaryembodiment is not meant to be limiting. All of the various embodimentsof thermal wells described herein may be used in conjunction withcassettes, such as exemplary cassette 2300.

FIG. 39 shows thermal wells 5100 installed in exemplary cassettemanifold 3900. Thermal well 5100 may be installed in exemplary cassettemanifold 3900 by use of the ways described herein, including adhesive,welding (ultrasonic and otherwise), o-ring, retaining plate, andotherwise. The thermal well 5100 used in connection with a cassette maybe of various shapes and configurations. However, referring now to FIG.4 for purposes of description, the embodiment of a thermal well 5100shown may be utilized in conjunction with a cassette. In the exemplaryembodiment shown in FIG. 4, the bottom zone 5406 is shaped to aid inpress fitting the thermal well into the sensor port 2304, 3905, and 3906shown in FIG. 39. Subject media may come into contact with the outsideof zone 5402 of the thermal well 5100 as described above. Thermal energyis transferred from the subject media to the thermal well 5100. As maybe seen with reference to FIG. 13A-B, the thermal energy can them befurther transferred to the tip 6002 of the sensing probe 6000. Thermalenergy is then conducted to the thermal sensor 6014. The thermal sensor6014 communicates via leads 6016 with equipment that can determine thetemperature of the subject media based on feedback of the thermal sensor6014. In embodiments where conductivity sensing is also desired, lead6018 communicates with equipment that can determine the conductivity ofthe subject media. With respect to determining the conductivity of thesubject media, in addition to the lead 6018, a second electricallead/contact (not shown) would also be used. The second lead could beany probe or apparatus capable of sensing capacitance of the subjectmedia, including, an electrical contact.

Heat transfer from the tip 6002 to the thermal sensor 6014 may beimproved by the use of a thermal epoxy or thermal grease 6022.

Many different embodiments of sensing apparatus may be used inconnection with a thermal well installed in a flexible cassettemanifold, including embodiments similar to those shown in FIGS. 14A-B,15, and 16, and described above.

In certain embodiments of sensor apparatus and sensor apparatus systemsused in conjunction with a flexible membrane cassette, a sensing probemay be installed directly into sensing ports 3904, 3905, and 3906 (shownin FIG. 39). In further embodiments of sensor apparatus and sensorapparatus systems used in conjunction with a flexible membrane, asensing probe may be used with a thermal well.

In embodiments in which cassette manifold 3900 is used in conjunctionwith a sensing probe attached to a house, it may be preferable forsensor ports 3904, 3905, and 3906 to be positioned in the bottom edge ofcassette manifold 3900 (the bottom edge as the cassette manifold isshown in FIG. 39). Positioning of the sensor ports 3904, 3905, and 3906along the bottom edge of exemplary cassette manifold 3900 (such thatsensor ports 2904, 3905, and 3906 and installed thermal wells 5100extend into the bottom fluid line 3903 of the cassette) may facilitateengagement with the sensor apparatus as shown in FIG. 28. In certain ofthese embodiments, the exemplary cassette manifold 3900 with installedthermal wells 5100 may be placed in position over sensor probes 6000,and then rotated vertically down and onto the sensor probes 6000.

While several geometries have been described, many others could be shownto achieve desired performance characteristics.

The sensing apparatus, in some embodiments, is used to senseconductivity of the subject media within a fluid line within a cassette.In some embodiments, this is in addition to temperature sensing. Inthose embodiments where both temperature and conductivity sensing isdesired, the sensing probe typically includes at least three leads,where two of these leads may be used for temperature sensing and thethird used for conductivity sensing.

Referring now to FIG. 21, for conductivity sensing, at least two sensors7102, 7104 are located in an area containing the subject media. In theembodiment shown, the area containing the subject media is a fluid path5104 inside a fluid line 5108. The conductivity sensors 7102, 7104 canbe one of the various embodiments of sensing probes as described above,or one of the embodiments of the sensor apparatus embodiments (includingthe thermal well) as described above.

Referring now to FIG. 28, sensing probes 6000 installed in thermal wells5100 in sensor ports 2305 and 2306 can be used for sensing theconductivity of the subject media located between sensor ports 2305 and2306 in fluid line 2303. However, in other embodiments, only one of thesensors is one of the embodiments of the sensor apparatus or one of theembodiments of the sensing probe, and the second sensor is anyelectrical sensor known in the art. Thus, in the systems describedherein, conductivity and temperature can be sensed through using eitherone of the sensor apparatus or one of the sensor probes as describedherein and a second capacitance sensor, or one of the sensor apparatusor one of the sensor probes as described herein and an electricalsensor.

For the various embodiments described herein, the cassette may be madeof any material, including plastic and metal. The plastic may beflexible plastic, rigid plastic, semi-flexible plastic, semi-rigidplastic, or a combination of any of these. In some of these embodimentsthe cassette includes one or more thermal wells. In some embodiments oneor more sensing probes and/or one or more other devices for transferringinformation regarding one or more characteristics of such subject mediaare in direct contact with the subject media. In some embodiments, thecassette is designed to hold fluid having a flow rate or pressure. Inother embodiments, one or more compartments of the cassette is designedto hold mostly stagnant media or media held in the conduit even if themedia has flow.

In some embodiments, the sensor apparatus may be used based on a need toseparate the subject media from the sensing probe. However, in otherembodiments, the sensing probe is used for temperature, conductivity,and/or other sensing directly with subject media.

In some embodiments, the thermal well may be part of a disposableportion of a device, machine, system or container. Thus, the thermalwell may be in direct contact with subject media and may be the onlycomponent that is contaminated by same. In these embodiments, thesensing probe may be part of a machine, device, system or container, andbe disposable or non-disposable.

With reference to FIG. 40, another embodiment of an exemplary sensormanifold is shown. A subject media may be contained in or flow throughcassette manifold 4000. Subject media may enter cassette manifold 4000via pre-molded tube connector 4001 a and exit the cassette manifold viapre-molded tube connector 4001 b. Between tube connector 4001 a and 4001b, there is a fluid path though the cassette (not shown). Likewise fluidpaths (not shown) extend between tube connectors 4002 a and 4002 b and4003 a and 4003 b.

Referring again to FIG. 40, in this exemplary embodiment of cassettesthat may be used in conjunction with the sensor apparatus and sensorapparatus systems described herein, the cassette includes a top plate, amidplate and a bottom plate. Fluid paths, such as the fluid pathextending between tube connectors 4001 a and 4001 b extend through themidplate. In the exemplary embodiment, the cassettes are formed byplacing the membranes in their correct locations, assembling the platesin order and laser welding the plates. The cassettes may be constructedof a variety of materials. Generally, in the various exemplaryembodiment, the materials used are solid and non flexible. In thepreferred embodiment, the plates are constructed of polysulfone, but inother embodiments, the cassettes are constructed of any other solidmaterial and in exemplary embodiment, of any thermoplastic.

Referring now to FIG. 40, in an exemplary embodiment of the cassettemanifold, sensors are incorporated into the cassette so as to discernvarious properties of subject media contained in or flowing through thecassette. In various embodiments one sensor may be included to sensetemperature and/or other properties of the subject media. In anotherembodiment, two sensors may be included, to sense temperature and/orconductivity and/or other properties of the subject media. In yetfurther embodiments, three or more sensors may be included. In someembodiments, such as sensor element 4004, one sensor element of the typegenerally described above is included. In other embodiments, the sensorsare located in the sensor block 4005. In this embodiment, a sensor block4005 is included as an area on the cassette manifold for sensor(s), suchas temperature sensors and/or conductivity sensors. The conductivitysensors and temperature sensor can be any conductivity or temperaturesensor in the art. In one embodiment, the conductivity sensor elements(or sensor leads) are graphite posts. In other embodiments, theconductivity sensors elements are posts made from stainless steel,titanium, or any other material of the type typically used for (orcapable of being used for) conductivity measurements. In certainembodiments, the conductivity sensors will include an electricalconnection that transmits signals from the sensor lead to a sensormechanism, controller or other device. In various embodiments, thetemperature sensor can be any of the temperature sensors commonly used(or capable of being used) to sense temperature.

However, in alternate embodiments, a combination temperature andconductivity sensor is used of the types described above. In suchalternate embodiments, thermal wells of the types described above may beinstalled in the cassette. In such embodiments, the thermal well may beinstalled in the cassette by use of any of the ways described herein,including adhesive, welding (ultrasonic and otherwise), o-ring,retaining plate, and otherwise.

Referring now to FIG. 40, two conductivity sensors 4006 and 4007 and thetemperature sensor 4008 are shown. In various embodiments, the sensors4006, 4007, and 4008 are in the fluid path (not shown) that extendsbetween tube connectors 4002 a and 4002 b and 4003 a and 4003 b.

3.5. Fluid Handling Systems and Methods Including Sensor Apparatus andSensor Apparatus Systems Utilized in Connection with a Sensor Manifold

In various embodiments of the inventions described herein, systems andmethods for fluid handling may be utilized that comprise sensorapparatus systems comprising a sensor manifold. Examples of suchembodiments may include systems and methods for the diagnosis,treatment, or amelioration of various medical conditions, includingembodiments of systems and methods involving the pumping, metering,measuring, controlling, and/or analysis of various biological fluidsand/or therapeutic agents, such as various forms of dialysis, cardiobi-pass, and other types of extracorporeal treatments and therapies.Further examples include fluid treatment and preparation systems,including water treatment systems, water distillation systems, andsystems for the preparation of fluids, including fluids utilizeddiagnosis, treatment, or amelioration of various medical conditions,such as dialysate.

Examples of embodiments of the inventions described herein may includedialysis systems and methods. More specifically, examples of embodimentsof the inventions described herein may include hemodialysis systems andmethods of the types described in U.S. patent application Ser. No.11/871,680, filed Oct. 12, 2007 entitled Pumping Cassette; U.S. patentapplication Ser. No. 12/072,908, filed Feb. 27, 2008 and issued as U.S.Pat. No. 8,246,826 on Aug. 21, 2012 and entitled Hemodialysis System andMethods; and U.S. patent application Ser. No. 12/038,648, filed Feb. 27,2008 and issued as U.S. Pat. No. 8,042,563 on Oct. 25, 2011 and entitledCassette System Integrated Apparatus.

In such systems and methods, the utilization of one or more sensormanifolds may allow subject media to be moved from one environment toanother environment that is more conducive to obtaining sensor readings.For example, the cassette manifold may be contained in an area that isless subject to various types of environment conditions, such astemperature and/or humidity, which would not be preferable for sensorapparatus such as a sensing probe. Alternatively, sensing apparatus andsensing apparatus system may be delicate and may be more prone tomalfunctions than other components of a system. Separating the sensorapparatus and the sensor apparatus systems from other components of thesystem by use of a sensor manifold may allow the sensing apparatus andsensing apparatus systems to be checked, calibrated, repaired orreplaced with minimal impact to other components in the system. Theability to check, calibrate, repair or replace the sensor manifold withminimal impact to the remainder of the system may be particularlyadvantageous when utilized in connection with the integrated cassettesystems and methods described in U.S. patent application Ser. No.12/072,908, filed Feb. 27, 2008 and issued as U.S. Pat. No. 8,246,826 onAug. 21, 2012 and entitled Hemodialysis System and Methods and U.S.patent application Ser. No. 12/038,648, filed Feb. 27, 2008 and issuedas U.S. Pat. No. 8,042,563 on Oct. 25, 2011 and entitled Cassette SystemIntegrated Apparatus. Alternatively, the sensor manifold may be replacedeither more or less frequently than other components of the system.

With reference to FIGS. 41-46, various other embodiments of an exemplarysensor manifold is shown. One or more subject media, preferably a liquidin these exemplary embodiments, may be contained in or flow throughcassette manifold 4100. For example, one subject media may entercassette manifold 4100 via pre-molded tube connector 4101 and exit thecassette manifold via pre-molded tube connector 4102. Between tubeconnector 4101 and 4102, there is a fluid path though the cassette (bestshown as fluid path 4225 in FIG. 42). Likewise fluid paths (shown asfluid paths 4223, 4220, 4222, 4224, and 4221 respectively in FIG. 42)extend between sets of tube connectors 4103 and 4104; 4105 and 4106;4107, 4108, and 4109; 4110 and 4111; and 4112 and 4113. In certainembodiments, each fluid path may contain subject media of differentcomposition or characteristics. In other embodiments, one or more fluidpaths may contain the same or similar subject media. In certainembodiments, the same subject media may be flowed through more than oneflow path at the same time to check and/or calibrate the sensorapparatus systems associated with such fluid paths.

Referring now to FIG. 43, in these exemplary embodiments of sensormanifold 4100 that may be used in conjunction with the sensor apparatusand sensor apparatus systems described herein, the cassette includes atop plate 4302 and a base 4301. Fluid paths, such as the fluid path 4225(as shown in FIG. 42) extending between tube connectors 4101 and 4102extend between the base and top plate. The cassettes may be constructedof a variety of materials. Generally, in the various exemplaryembodiment, the materials used are solid and non flexible. In thepreferred embodiment, the plates are constructed of polysulfone, but inother embodiments, the cassettes are constructed of any other solidmaterial and in exemplary embodiments, of any thermoplastic. Preferredembodiments of sensor manifold 4100 may be fabricated utilizing thesystems and methods described in U.S. patent application Ser. No.12/038,648, filed Feb. 27, 2008 and issued as U.S. Pat. No. 8,042,563 onOct. 25, 2011 and entitled Cassette System Integrated Apparatus.

Referring again to FIG. 43, in these exemplary embodiments of sensormanifolds that may be used in conjunction with the sensor apparatus andsensor apparatus systems described herein, the sensor manifold 4100 mayalso include printed circuit board (PCB) 4304 and a PCB cover 4305.Various embodiments may also include connector 4303 (also shown in FIGS.41 and 44B) which may be utilized to mechanically connect the cassettemanifold 4100 to the system, such as a hemodialysis system. Cassettemanifold 4100 may also utilize various means to hold the layers ofsensor manifold 4100 together as a unit. In various embodiments, asshown in FIG. 43, connectors 4306 (also shown in FIG. 44B), which in oneembodiment is a screw, but in other embodiments may be any means forconnection, are utilized, but any means known to one of skill in theart, such as other types of screws, welds, clips, clamps, and othertypes of chemical and mechanical bonds may be utilized.

Referring now to FIG. 44A, in exemplary embodiments of the sensormanifold 4100, tube connectors, such as tube connector 4401, is utilizedto bring subject media into or remove subject media from fluid path4402. Sensing probes, such as sensing probe 4404 extending into fluidpath 4402, are incorporated into sensor manifold 4100 so as to determinevarious properties of the subject media contained in or flowing throughthe particular fluid path in the sensor manifold. In various embodimentsone sensing probe may be utilized to sense temperature and/or otherproperties of the subject media. In another embodiment, two sensingprobes may be utilized to sense temperature and/or conductivity and/orother properties of the subject media. In yet further embodiments, threeor more sensing probes may be included. In some embodiments, one or morecombination temperature and conductivity sensing probes of the typesgenerally described herein may be utilized. In other embodiments, theconductivity sensors and temperature sensor can be any conductivity ortemperature sensor in the art. In one embodiment, the conductivitysensor elements (or sensor leads) are graphite posts. In otherembodiments, the conductivity sensors elements are posts made fromstainless steel, titanium, or any other material of the type typicallyused for (or capable of being used for) conductivity measurements. Incertain embodiments, the conductivity sensors will include an electricalconnection that transmits signals from the sensor lead to a sensormechanism, controller or other device. In various embodiments, thetemperature sensor can be any of the temperature sensors commonly used(or capable of being used) to sense temperature.

Referring again to FIG. 44A, sensing probe 4404 is electricallyconnected to PCB 4405. In certain embodiments, an electricallyconductive epoxy is utilized between sensor element 4404 and PCB 4405 toensure appropriate electrical connection, although other means known tothose of skill in the art may be used to obtain an appropriateelectrical connection between sensor element 4404 and PCB 4405. PCB 4405is shown with edge connector 4406. In various embodiments, edgeconnector 4406 may be used to transmit sensor information from cassettemanifold 4100 to the main system, such as embodiments of thehemodialysis system described in U.S. patent application Ser. No.12/072,908, filed Feb. 27, 2008 and issued as U.S. Pat. No. 8,246,826 onAug. 21, 2012 and entitled Hemodialysis System and Methods. Edgeconnector 4406 may be connected to a media edge connector (such as mediaedge connector 4601 shown in FIG. 46). In various embodiments, mediaedge connector 4601 may be installed in a hemodialysis machine (notshown). In such embodiments, guide tracks 4310 and 4311 (as shown inFIG. 43) may be utilized to assist in the connection of edge connector4406 and media edge connector 4601. Various embodiments may also includeconnector 4303 (as shown in FIGS. 41, 43 and 44B) which may be utilizedto mechanically connect the cassette manifold 4100 to the system, suchas a hemodialysis system.

Referring again to FIG. 44A, air trap 4410 is shown. In certainembodiments, an air trap, such as air trap 4410, may be utilized to trapand purge air in the system. As may be best shown in FIG. 42, subjectmedia may flow through fluid path 4222 between tube connectors 4107 and4109 in sensor manifold 4100. As the flow of the subject media is slowedaround the turn in fluid path 4222 (near tube connector 4108), air maybe removed from the subject media through connector 4108.

Referring now to FIG. 44B, PCB cover 4305 is shown. PCB cover 4305 maybe connected to sensor manifold 4100 by connectors 4306. Edge connector4406 is also shown.

In accordance with certain embodiments, sensor manifold 4100 is passivewith respect to control of the fluid flow. In such embodiments, sensormanifold 4100 does not contain valves or pumping mechanisms to controlthe flow of the subject media. In such embodiments, the flow of thesubject media may be controlled by fluid control apparatus external tosensor manifold 4100. In other embodiments, the sensor manifold mayinclude one or more mechanical valves, pneumatic valves or other type ofvalve generally used by those of skill in the art. In such embodiments,the sensor manifold may include one or more pumping mechanisms,including pneumatic pumping mechanisms, mechanical pumping mechanisms,or other type of pumping mechanisms generally used by those of skill inthe art. Examples of such valves and pumping mechanisms may include thevalves and pumping mechanisms described in U.S. patent application Ser.No. 11/871,680, filed Oct. 12, 2007 entitled Pumping Cassette; U.S.patent application Ser. No. 12/072,908, filed Feb. 27, 2008 and issuedas U.S. Pat. No. 8,246,826 on Aug. 21, 2012 and entitled HemodialysisSystem and Methods; and U.S. patent application Ser. No. 12/038,648,filed Feb. 27, 2008 and issued as U.S. Pat. No. 8,042,563 on Oct. 25,2011 and entitled Cassette System Integrated Apparatus.

Referring now to FIG. 45, tube connector 4401 is shown in base 4301. Topplate 4302 is shown, along with connector 4303. Sensing probes, such assensing probe 4501, extend through top plate 4302 into fluid path 4503.Sensing probe 4501 may be various types of sensors, including theembodiments of sensing probes generally shown in FIGS. 8 and 9 herein.

The sensing probes, such as sensing probe 4501, may be all the same, maybe individually selected from various sensors based on the type offunction to be performed, or the same probe may be individually modifiedbased on the type of function to be performed. Similarly, theconfiguration of the fluid paths, such as the length of the fluid pathand the shape of the fluid path, may be selected based on the functionto be performed. By way of example, to detect the temperature of thesubject media in a fluid path, a temperature sensor, such as athermistor, may be used. Again, by way of example, to measure theconductivity of the subject media, one sensing probe configured tomeasure temperature and conductivity, such as sensing probes of the typegenerally shown in FIGS. 8 and 9, and one sensing probe configured onlyto measure conductivity may be utilized. In other embodiments, two ormore sensing probes configured to measure both temperature andconductivity, such as sensing probes of the type generally shown inFIGS. 8 and 9, may be utilized. In various embodiments of suchconfigurations, by way of example, the second temperature sensor may bepresent but not utilized in normal operation, or the second temperaturemay be utilized for redundant temperature measurements, or the or thesecond temperature may be utilized for redundant temperaturemeasurements.

Referring again to FIG. 45, PCB 4502 is shown with electrical connection4503. As further shown in FIG. 46, PCB 4602 is shown with electricalconnection 4603 for connection to a sensing probe (shown as 4501 in FIG.45). PCB 4602 also contains opening 4604 for attachment to top plate(shown as 4305 in FIG. 45). In certain embodiments, electricalconnection 4603 is mounted onto, or manufactured with, PCB 4602 with airgap 4606. In such embodiments, air gap 4606 may be utilized to provideprotection to the electrical connection between sensing probe 4501 andPCB 4602 by allowing shrinking and expansion of the various componentsof sensor manifold 4100 with lesser impact to PCB 4602.

Referring again to FIG. 46, PCB 4602 is also shown with edge connector4605. As described herein, edge connector 4605 may interface with edgeconnector receiver 4601, which may be connected to the system, such asthe hemodialysis system, to which sensor manifold 4100 interfaces.

Various embodiments of exemplary sensor manifold 4100 shown in FIGS.41-46 may be utilized in conjunction with hemodialysis systems andmethods described in U.S. patent application Ser. No. 11/871,680, filedOct. 12, 2007 entitled Pumping Cassette; U.S. patent application Ser.No. 12/072,908, filed Feb. 27, 2008 and issued as U.S. Pat. No.8,246,826 on Aug. 21, 2012 and entitled Hemodialysis System and Methods;and U.S. patent application Ser. No. 12/038,648, filed Feb. 27, 2008 andissued as U.S. Pat. No. 8,042,563 on Oct. 25, 2011 and entitled CassetteSystem Integrated Apparatus In certain embodiments, sensor manifold 4100contains all of the temperature and conductivity sensors shown in FIG.47. FIG. 47 depicts a fluid schematic in accordance with one embodimentof the inventions described in the patent applications reference above.

By way of example, in various embodiments, the temperature andconductivity of the subject media at position 4701 as shown in FIG. 47may be determined utilizing sensor manifold 4100. In such embodiments,subject media flows into tube connector 4105 (as shown in FIG. 41)through fluid path 4220 (as shown in FIG. 42) and exits at tubeconnector 4106 (as shown in FIG. 41). The conductivity of the subjectmedia is measured by two sensing probes (not shown) extending into fluidpath 4220, at least one of which has been configured to include atemperature sensing element, such as a thermistor. The conductivitymeasurement or the temperature measurement of the subject media may beutilized to determine and/or correlate a variety of information ofutility to the hemodialysis system. For example, in various embodimentsat position 4701 in FIG. 47, the subject media may be comprised of waterto which a bicarbinated based solution has been added. Conductivity ofthe subject media at position 4701 may be utilized to determine if theappropriate amount of the bicarbonate based solution has been addedprior to position 4701. In certain embodiments, if the conductivitymeasurement deviates from a predetermined range or deviates from apredetermined measurement by more than a predetermined amount, then thesubject media may not contain the appropriate concentration of thebicarbonate based solution. In such instances, in certain embodiments,the hemodialysis system may be alerted.

Again, by way of example, in various embodiments, the conductivity ofthe subject media at position 4702 as shown in FIG. 47 may be determinedutilizing sensor manifold 4100. In such embodiments, subject media flowsinto tube connector 4112 (as shown in FIG. 41) through fluid path 4221(as shown in FIG. 42) and exits at tube connector 4113 (as shown in FIG.41). The conductivity of the subject media is measured by two sensingprobes (not shown) extending into fluid path 4221, at least one of whichhas been configured to include a temperature sensing element, such as athermistor. The conductivity measurement or the temperature measurementof the subject media may be utilized to determine and/or correlate avariety of information of utility to the hemodialysis system. Forexample, in various embodiments at position 4702 in FIG. 47, the subjectmedia may be comprised of water to which a bicarbinated based solutionand then an acid based solution has been added. Conductivity of thesubject media at position 4702 may be utilized to determine if theappropriate amount of the acid based solution (and the bicarbonate basedsolution in a previous step) has been added prior to position 4702. Incertain embodiments, if the conductivity measurement deviates from apredetermined range or deviates from a predetermined measurement by morethan a predetermined amount, then the subject media may not contain theappropriate concentration of the acid based solution and the bicarbonatebased solution. In such instances, in certain embodiments, thehemodialysis system may be alerted.

By way of further example, in various embodiments, the temperature andconductivity of the subject media at position 4703 as shown in FIG. 47may be determined utilizing sensor manifold 4100. In such embodiments,subject media may flow into or out of tube connector 4107 (as shown inFIG. 41) through fluid path 4222 (as shown in FIG. 42) and may flow intoor out of tube connector 4109 (as shown in FIG. 41). As describedherein, air may be removed from the subject media as it moves past theturn in fluid path 4222. In such instances, a portion of the subjectmedia may be removed through tube connector 4108 to the drain, bringingwith it air from the air trap. The conductivity of the subject media ismeasured by two sensing probes (not shown) extending into fluid path4222, at least one of which has been configured to include a temperaturesensing element, such as a thermistor. The conductivity measurement orthe temperature measurement of the subject media may be utilized todetermine and/or correlate a variety of information of utility to thehemodialysis system. For example, in various embodiments, theconductivity measurement at position 4703 in FIG. 47 may be utilized tocorrelate to the clearance of the dialyzer. In such instances, incertain embodiments, this information may then be sent to thehemodialysis system.

Again, by way of further example, in various embodiments, thetemperature of the subject media at position 4704 as shown in FIG. 47may be determined utilizing sensor manifold 4100. In such embodiments,subject media flows into tube connector 4103 (as shown in FIG. 41)through fluid path 4223 (as shown in FIG. 42) and exits at tubeconnector 4104 (as shown in FIG. 41). The temperature of the subjectmedia is measured by one or more sensing probes (not shown) extendinginto fluid path 4223. The temperature measurement of the subject mediaat position 4704 may be utilized to determine and/or correlate a varietyof information of utility to the hemodialysis system. For example, invarious embodiments at position 4704 in FIG. 47, the temperature of thesubject media is determined down stream of a heating apparatus 4706. Ifthe temperature deviates from a predetermined range or deviates from apredetermined measurement by more than a predetermined amount, then thehemodialysis system may be alerted. For example in certain embodiments,the subject media may be re-circulated through the heating apparatus4706 until the temperature of the subject media is within apredetermined range.

Again, by way of further example, in various embodiments, thetemperature and conductivity of the subject media at position 4705 asshown in FIG. 47 may be determined utilizing sensor manifold 4100. Insuch embodiments, subject media flows into tube connector 4110 (as shownin FIG. 41) through fluid path 4224 (as shown in FIG. 42) and exits attube connector 4111 (as shown in FIG. 41). The conductivity of thesubject media is measured by two sensing probes (not shown) extendinginto fluid path 4224, at least one of which has been configured toinclude a temperature sensing element, such as a thermistor. Theconductivity measurement or the temperature measurement of the subjectmedia may be utilized to determine and/or correlate a variety ofinformation of utility to the hemodialysis system. For example, thetemperature and conductivity measurement at position 4705 may be used asa further safety check to determine if the temperature, conductivity,and, by correlation, the composition of, the subject media is withinacceptable ranges prior to the subject media reaching the dialyzer 4707and, thus, the patient. In certain embodiments, if the temperatureand/or conductivity measurement deviates from a predetermined range ordeviates from a predetermined measurement by more than a predeterminedamount, then the hemodialysis system may be alerted.

For the various embodiments described herein, the cassette may be madeof any material, including plastic and metal. The plastic may beflexible plastic, rigid plastic, semi-flexible plastic, semi-rigidplastic, or a combination of any of these. In some of these embodimentsthe cassette includes one or more thermal wells. In some embodiments oneor more sensing probes and/or one or more other devices for transferringinformation regarding one or more characteristics of such subject mediaare in direct contact with the subject media. In some embodiments, thecassette is designed to hold fluid having a flow rate or pressure. Inother embodiments, one or more compartments of the cassette is designedto hold mostly stagnant media or media held in the conduit even if themedia has flow.

In some embodiments, the sensor apparatus may be used based on a need toseparate the subject media from the sensing probe. However, in otherembodiments, the sensing probe is used for temperature, conductivity,and/or other sensing directly with subject media.

Although the above discussion discloses various exemplary embodiments ofthe invention, it should be apparent that those skilled in the art canmake various modifications that will achieve some of the advantages ofthe invention without departing from the true scope of the invention.While the principles of the invention have been described herein, it isto be understood by those skilled in the art that this description ismade only by way of example and not as a limitation as to the scope ofthe invention. Other embodiments are contemplated within the scope ofthe present invention in addition to the exemplary embodiments shown anddescribed herein. Modifications and substitutions by one of ordinaryskill in the art are considered to be within the scope of the presentinvention.

We claim:
 1. A multi-fluid flow path containing a sensing system forsensing subject media comprising: a sensor manifold comprising a housingenclosing at least a first fluid flow path and a second fluid flow pathwhich are fluidically isolated from each other during use of the sensingsystem, each of said first and second fluid flow paths having a fluidinlet port and a fluid outlet port; and a sensor apparatus for sensingconductivity of subject media in each of said first and second fluidflow paths, wherein the sensor apparatus comprises a separate group ofconductivity sensors associated with each of said first and second fluidflow paths, each group of conductivity sensors comprising at least twoconductivity sensing probes spaced apart from one another, wherein thesensor manifold comprises a top plate and a base, the top plate beingsealingly engaged with the base to define the volumes of the fluid flowpaths, wherein the sensing probes penetrate the top plate to extend intothe fluid flow paths.
 2. A sensing system according to claim 1, whereinthe sensing probes extend into fluid flow paths with which they areassociated.
 3. A sensing system according to claim 1, wherein the one ormore conductivity sensing probes comprises a thermistor.
 4. A sensingsystem according to claim 1, wherein the sensor apparatus comprises aprinted circuit board, and wherein sensing probes are connected to theprinted circuit board and extend into the fluid flow paths.
 5. A sensingsystem according to claim 4, wherein the printed circuit board comprisesan edge connector configured to connect with a corresponding connectorreceiver for transmitting electrical signals to and/or from the sensingprobes.
 6. A sensing system according to claim 1, wherein the subjectmedia comprises a liquid.
 7. A sensing system according to claim 6,wherein the liquid comprises dialysate solution.
 8. A multi-fluid flowpath containing a sensing system for sensing subject media comprising: asensor manifold comprising a housing enclosing at least a first fluidflow path and a second fluid flow path which are fluidically isolatedfrom each other during use of the sensing system, each of said first andsecond fluid flow paths having a fluid inlet port and a fluid outletport; and a sensor apparatus for sensing conductivity of subject mediain each of said first and second fluid flow paths, wherein the sensorapparatus comprises a separate group of conductivity sensors associatedwith each of said first and second fluid flow paths, each group ofconductivity sensors comprising at least two conductivity sensing probesspaced apart from one another, wherein the sensor manifold is free ofvalves and pumping mechanisms.
 9. A sensing system according to claim 8,wherein the sensing probes extend into fluid flow paths with which theyare associated.
 10. A sensing system according to claim 8, wherein theone or more conductivity sensing probes comprises a thermistor.
 11. Asensing system according to claim 8, wherein the sensor apparatuscomprises a printed circuit board, and wherein sensing probes areconnected to the printed circuit board and extend into the fluid flowpaths.
 12. A sensing system according to claim 11, wherein the printedcircuit board comprises an edge connector configured to connect with acorresponding connector receiver for transmitting electrical signals toand/or from the sensing probes.
 13. A sensing system according to claim8, wherein the subject media comprises a liquid.
 14. A sensing systemaccording to claim 13, wherein the liquid comprises dialysate solution.